Twin cities - wikipedia Twin cities This article is about the general concept of `` twin cities ''. For the area typically called the `` Twin Cities '' in the United States, see Minneapolis -- Saint Paul. For other uses, see Twin city ( disambiguation ). This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( March 2011 ) Twin cities are a special case of two cities or urban centres that are founded in close geographic proximity and then grow into each other over time, losing most of their mutual buffer zone. There are no precise criteria for twin - cityhood, but to be considered twin cities, the cities involved have to have a similar administrative status and somewhat comparable sizes ; a suburb of a much larger population center is usually not considered to form a twin city with it. For example, South San Francisco ( population about 65,000 ) is not considered a twin city with San Francisco ( population about 850,000 ). However, cities considered twinned by proximity do not necessarily match demographically, economically, or politically. In many historical cases, cities that grew into each other 's space lost their individual identities, and the border or barrier originally separating them became almost irrelevant. An 1873 case of twin cities merging to become a united city is Budapest in Hungary, which began as two settlements ( Buda and Pest ) facing each other across the Danube at a strategic fording place along a trade route. In China, the three ancient cities of Hankou, Hanyang, and Wuchang, separated by the junction of the Yangtze and Hanjiang rivers, were joined in 1927 into the single entity of Wuhan. Twin cities may share an airport into whose airport codes are integrated the component initials e.g. BWI ( Baltimore - Washington ), DFW ( Dallas -- Fort Worth ), LBA ( Leeds -- Bradford ), MSP ( Minneapolis -- Saint Paul, Minnesota ), RDU ( Raleigh and Durham, NC ), and CAK ( Akron -- Canton, Ohio ). In some cases, such as Albury / Wodonga in Australia, the two cities are permanently divided by a state border, often one that strictly adheres to a geographical landmark, such as the Murray River that divides New South Wales from Victoria, and thus Albury from Wodonga. In other cases twin cities can be divided by an international border, but retain a cultural and historical similarity, for example Haparanda ( Sweden ) and Tornio ( Finland ), Leticia ( Colombia ) and Tabatinga ( Brazil ) or Valga ( Estonia ) and Valka ( Latvia ). Contents 1 Examples 1.1 Americas 1.1. 1 North America 1.1. 2 South America 1.1. 3 International 1.1. 4 Historic 1.2 Asia 1.2. 1 Current 1.2. 2 Historic 1.3 Europe 1.3. 1 Current 1.3. 2 International 1.3. 3 Historic 1.4 Oceania 2 Tri-cities 3 Quad cities 4 More than four cities 5 Examples of cities formed by amalgamation 5.1 Asia 5.2 Europe 5.3 North America 6 Fictional twin cities 7 See also 8 Notes 9 References Examples Cross-border example of twin cities : Plaza Internacional of the Frontera de la Paz. On the left, Santana do Livramento ( Brazil ) ; on the right, Rivera ( Uruguay ). This article may contain indiscriminate, excessive, or irrelevant examples. Please improve the article by adding more descriptive text and removing less pertinent examples. See Wikipedia 's guide to writing better articles for further suggestions. ( November 2009 ) Americas North America Canada Battleford and North Battleford, Saskatchewan `` The Battlefords '' Dartmouth, Nova Scotia and Halifax Gatineau, Quebec and Ottawa, Ontario Also Known as the Ottawa - Gatineau Metropolitan Area Kitchener - Cambridge - Waterloo United States Alcoa and Maryville, Tennessee Allentown and Bethlehem, Pennsylvania Auburn and Lewiston, Maine Auburn and Opelika, Alabama Benton Harbor and St. Joseph, Michigan Bloomington and Normal, Illinois Bluefield, Virginia and Bluefield, West Virginia Bossier City and Shreveport, Louisiana Bristol, Tennessee, and Bristol, Virginia Bryan and College Station, Texas Centralia and Chehalis, Washington Champaign and Urbana, Illinois Colorado City, Arizona and Hildale, Utah Dallas and Fort Worth Duluth, Minnesota, and Superior, Wisconsin Durham and Raleigh, North Carolina Fargo, North Dakota, and Moorhead, Minnesota Fitchburg and Leominster, Massachusetts Grand Forks, North Dakota and East Grand Forks, Minnesota Greensboro and Winston - Salem, North Carolina Greenville and Spartanburg, South Carolina Gulfport, Mississippi and Biloxi, Mississippi Hartford, Connecticut and Springfield, Massachusetts Killeen and Temple, Texas Lafayette and West Lafayette, Indiana Lancaster and Palmdale, California Lansing ( west ), and East Lansing, Michigan Macon and Warner Robins, Georgia Marinette, Wisconsin and Menominee, Michigan Midland and Odessa, Texas Minneapolis and Saint Paul, Minnesota Monroe and West Monroe, Louisiana Montague and Whitehall, Michigan Norfolk and Virginia Beach, Virginia Portland and South Portland, Maine Petersburg and Richmond, Virginia Reno and Sparks, Nevada Scranton and Wilkes - Barre, Pennsylvania Sherman and Denison, Texas South Bend and Mishawaka, Indiana St. Petersburg, Florida and Tampa Texarkana, Arkansas and Texarkana, Texas Union City, Indiana and Union City, Ohio Wahpeton, North Dakota and Breckenridge, Minnesota Mexico -- United States border San Diego, California, United States and Tijuana, Baja California, Mexico Calexico, California, United States and Mexicali, Baja California, Mexico Yuma, Arizona, United States and San Luis Rio Colorado, Sonora, Mexico Nogales, Arizona, United States and Nogales, Sonora, Mexico Douglas, Arizona, United States and Agua Prieta, Sonora, Mexico Columbus, New Mexico, United States and Las Palomas, Chihuahua, Mexico El Paso, Texas, United States and Ciudad Juarez, Chihuahua, Mexico Presidio, Texas, United States and Ojinaga, Chihuahua, Mexico Del Rio, Texas, United States and Ciudad Acuña, Coahuila, Mexico Eagle Pass, Texas, United States and Piedras Negras, Coahuila, Mexico Laredo, Texas, United States and Nuevo Laredo, Nuevo Leon, Mexico Mcallen, Texas, United States and Reynosa, Tamaulipas, Mexico Brownsville, Texas, United States and Matamoros, Tamaulipas, Mexico Canada -- United States border Sault Ste. Marie, Michigan and Sault Ste. Marie, Ontario Detroit, Michigan and Windsor, Ontario Niagara Falls, New York and Niagara Falls, Ontario Buffalo, New York and Fort Erie, Ontario South America Argentina Carmen de Patagones and Viedma Paraná, Entre Ríos and Santa Fe Brazil Juazeiro and Petrolina Olinda and Recife Vila Velha and Vitória Chile Concepción and Talcahuano Coquimbo and La Serena Valparaiso and Viña del Mar Peru Callao and Lima Venezuela Guarenas and Guatire Acarigua and Araure International Examples, sharing names or similar names, across an international border include : Chuí, Brazil ; Chuy, Uruguay Niagara Falls, Ontario, Canada ; Niagara Falls, New York, United States North Portal, Saskatchewan, Canada ; Portal, North Dakota, United States Sault Ste. Marie, Ontario, Canada ; Sault Ste. Marie, Michigan, United States Boquillas del Carmen, Coahuila, Mexico ; Boquillas, Texas, United States Naco, Sonora, Mexico ; Naco, Arizona, United States Nogales, Sonora, Mexico ; Nogales, Arizona, United States Nuevo Laredo, Tamaulipas, Mexico ; Laredo, Texas, United States Nuevo Progreso, Río Bravo, Tamaulipas, Mexico ; Progreso, Texas, United States San Luis Río Colorado, Sonora, Mexico ; San Luis, Arizona, United States Tecate, Baja California, Mexico ; Tecate, California, United States Calexico, California ; Mexicali, Baja California -- see Calexico -- Mexicali Pairs with unrelated names San Diego and Tijuana -- see San Diego -- Tijuana Detroit, Michigan and Windsor, Ontario -- see Detroit -- Windsor Douglas, Arizona and Agua Prieta, Sonora Brownsville, Texas and Matamoros, Tamaulipas -- see Matamoros -- Brownsville Metropolitan Area Eagle Pass, Texas and Piedras Negras, Coahuila Del Rio, Texas and Ciudad Acuña, Coahuila Presidio, Texas and Manuel Ojinaga, Chihuahua El Paso, Texas and Ciudad Juárez, Chihuahua -- see El Paso -- Juárez Historic Brooklyn, New York and New York City - until incorporation as a single city in 1898 - as noted in `` The New Colossus '', inscribed on a plaque at the Statue of Liberty. Lloydminster, Alberta / Saskatchewan Thunder Bay, Ontario ( formed by the amalgamation of Fort William and Port Arthur, Ontario in 1970 ) Asia Current Dhaka and Gazipur, Bangladesh Guangzhou and Foshan, People 's Republic of China Macau and Zhuhai, People 's Republic of China Ahmedabad and Gandhinagar, India Allahabad and Naini, India Cuttack and Bhubaneswar, India Munger and Jamalpur, India Durg and Bhilai, India Hubli and Dharwad, India Hyderabad and Secunderabad, Telangana, India Vijayawada and Amaravati, Andhra Pradesh, India Kankroli and Rajsamand, India Kochi and Ernakulam, India Kolkata and Howrah, India Mumbai and Navi Mumbai, India Pune and Pimpri - Chinchwad, India Harihar and Davangere, Karnataka, India Jalpaiguri and Siliguri, West Bengal, India Asansol and Durgapur, West Bengal, India Shivamoga and Bhadravati, Karnataka, India Ranchi and Hatia, India Tiruchirappalli and Srirangam, Tamil Nadu, India Tirunelveli and Palayamkottai, Tamil Nadu, India Seleucia and Ctesiphon, Iraq Tel Aviv and Jaffa, Israel Okayama and Kurashiki, Japan Tsukuba and Tsuchiura, Japan Nasushiobara and Otawara, Japan Kamisu and Kashima, Japan Beirut and Jounieh, Lebanon Kathmandu, Patan and Bhaktapur, Nepal Bharatpur and Narayangarh, Nepal Rawalpindi and Islamabad, Pakistan Jhelum and Sarai Alamgir, Pakistan Ramallah and al - Bireh, Palestine Dipolog and Dapitan, Philippines Taipei and New Taipei, Republic of China ( Taiwan ) Dammam and Khobar, Saudi Arabia Seoul and Incheon, South Korea Bangkok and Nonthaburi, Thailand Chiang Mai and Lamphun, Thailand Songkhla and Hatyai, Thailand Historic Chirala - Perala, India Victoria and Kowloon, colonial Hong Kong - although, in both colonial Hong Kong and the Hong Kong Special Administrative Region, Victoria is the only city recognised by law ; they were widely considered to be separate cities until at least the mid-1970s Saigon and Cholon, merged into Saigon - Cholon, now Ho Chi Minh City. Wuhan ( merger of Wuchang, Hankou, Hanyang ) Europe Current Aalborg and Nørresundby, Denmark Bournemouth and Poole, England Brighton and Hove, England Chatham and Rochester, England Leeds and Bradford, England Manchester and Salford, England Newcastle - upon - Tyne and Gateshead, England Porto and Vila Nova de Gaia, Portugal Póvoa de Varzim and Vila do Conde, Portugal Ludwigshafen and Mannheim, Germany Mainz and Wiesbaden, Germany Ulm and Neu - Ulm, Germany Sindelfingen and Böblingen, Germany Frankfurt and Offenbach, Germany Nuremberg and Fuerth, Germany Rotterdam and The Hague, The Netherlands Fredrikstad and Sarpsborg, Norway Porsgrunn and Skien, Norway Sandnes and Stavanger, Norway Słupsk and Ustka, Poland Novi Sad and Petrovaradin, Serbia Zemun and New Belgrade, Serbia Alcobendas and San Sebastián de los Reyes, Spain Santa Cruz de Tenerife and San Cristóbal de la Laguna, Spain Elda and Petrer, Spain Gothenburg and Mölndal, Sweden Jönköping and Huskvarna, Sweden Athens and Piraeus, Greece International Strasbourg, France and Kehl, Germany Frankfurt ( Oder ), Germany and Słubice, Poland Bad Radkersburg, Austria and Gornja Radgona, Slovenia Comines, Belgium and Comines, France Mouscron, Belgium and Tourcoing, France Wervik, Belgium and Wervicq - Sud, France Těšín, Czech Republic and Cieszyn, Poland Copenhagen, Denmark and Malmö, Sweden Narva, Estonia and Ivangorod, Russia Valga, Estonia and Valka, Latvia Tornio, Finland and Haparanda, Sweden Hendaye, France and Irun, Spain Görlitz, Germany and Zgorzelec, Poland Guben, Germany and Gubin, Poland Heringsdorf, Germany and Świnoujście, Poland Gorizia, Italy and Nova Gorica, Slovenia Kerkrade, The Netherlands and Herzogenrath, Germany Komárno, Slovakia and Komárom, Hungary Historic City of London and City of Westminster, England. Absorbed into London. Buda and Pest. United into Budapest. Barmen and Elberfeld, Germany. United into Wuppertal. Bielsko and Biała, Poland. United into Bielsko - Biała. Knokke and Heist - aan - Zee. United into Knokke - Heist. Gradec and Kapto l. United into Zagreb. Oceania Albury and Wodonga, Australia Canberra and Queanbeyan, Australia Gold Coast and Tweed Heads, Australia Forster and Tuncurry, Australia Harden and Murrumburrah, Australia Kalgoorlie and Boulder, Australia Napier and Hastings, New Zealand Perth and Fremantle, Australia Townsville and Thuringowa, Australia Parramatta and Sydney, Australia Tri-cities Main article : Tri-Cities ( disambiguation ) Brisbane ; Logan ; Ipswich, Queensland Australia Chandigarh ; Mohali ; and Panchkula, India Stockholm ; Solna ; and Sundbyberg, Sweden San Jose ; San Francisco ; and Oakland, California New York, New York ; Newark ; and Jersey City, New Jersey Gdańsk ; Gdynia ; and Sopot, Poland Greensboro ; Winston - Salem ; and High Point, North Carolina, the cities ' collective metropolitan area is often called the Piedmont Triad Raleigh ; Durham ; and Chapel Hill, North Carolina, the cities ' collective metropolitan area is often called the Research Triangle Allentown ; Bethlehem ; and Easton, Pennsylvania, the cities ' collective metropolitan area is often called the Lehigh Valley Dallas ; Fort Worth ; and Arlington, Texas Warangal ; Hanamkonda ; Kazipet, India Pasco ; Richland ; and Kennewick, Washington Dubai ; Sharjah ; and Ajman, United Arab Emirates Kitchener ; Waterloo ; and Cambridge, Ontario, the cities ' collective metropolitan area is often called the Kitchener - Waterloo or simply K-W Bay City ; Saginaw ; and Midland, Michigan, the cities ' collective metropolitan area is often called Saginaw Valley and the MBS Regions Temiskaming Shores, Ontario, Canada - Amalgamated the former municipalities of Cobalt, Haileybury and New Liskeard Quad cities In North Carolina, the Unifour : Hickory, Lenoir, Morganton and Alexander County Quad Cities of Davenport and Bettendorf, Iowa, and Rock Island and Moline, Illinois. It also includes a fifth member, East Moline, Illinois. The Florence - Muscle Shoals Metropolitan Area in Alabama is locally referred to as `` the Quad Cities '', with Florence, Muscle Shoals, Sheffield, and Tuscumbia. Formerly, when Muscle Shoals was a mere village, this region was known a `` Tri-Cities '', Alabama. Actually, they are all incorporated as towns except for Florence. The Quad Cities of Minnesota consist of Virginia, Eveleth, Gilbert, and Mountain Iron. The cities of Pullman, Washington, Moscow, Idaho, Clarkston, Washington, and Lewiston, Idaho have marketed themselves as `` Quad Cities. '' Pattaya - Chonburi Metropolitan Area consists of the City of Pattaya, Town of Chonburi, Portal town of Laem Chabang and Town of Sattahip on the west coast of Chonburi Province, Thailand More than four cities In the US state of Virginia : Norfolk ; Chesapeake ; Hampton ; Newport News ; Portsmouth ; Suffolk ; and Virginia Beach, the cities ' collective metropolitan area is often called Hampton Roads Ruhr district ( Germany ) : consisting of Dortmund, Essen, Duisburg, Bochum, Oberhausen, Mühlheim, Bottrop, Gelsenkirchen and Herne in its core. Examples of cities formed by amalgamation Asia Delhi, India : What used to be Old Delhi, New Delhi, and a collection of smaller villages has now grown into the current megalopolis that we see today, also known as the National Capital Region ( NCR ) Lahore, the second largest city of Pakistan, has, as of 2013, grown out so much that small towns by this giant city, such as Shahdara, have been absorbed in its city limits. Wuhan in China consists of the towns of Wuchang, Hankou, and Hanyang in Hubei Province. Islamabad, the capital city of Pakistan, has been expanded to include smaller towns including Rawat in its territory. Bangkok, the capital and largest city of Thailand, was created in 1971, when the previous Bangkok province ( Phra Nakhon ) was merged with Thonburi province. Fukuoka in Japan, a city of 1.4 million people, formerly the twin cities of Hakata and Fukuoka until the late 19th century. Saitama in Japan, a city of 1.2 million people, created in 2001 by the merger of the cities of Urawa, Omiya, Yono, and later Iwatsuki. Urawa and Omiya could formerly have been considered twin cities. Kitakyushu in Japan, a city of 900,000 people, created in 1963 by the merger of Yahata, Kokura, Moji, Wakamatsu, and Tobata. Yahata and Kokura had formerly been major cities in their own right. The cities of Saigon and Cholon merged in 1931 to form a single city named Saigon - Cholon ; in 1956, the name Cholon was dropped and the city became known as Saigon ( now Ho Chi Minh City ). Europe London grew from its cores in the City of London and the City of Westminster to encompass many other towns and villages within neighbouring counties and absorbed almost the whole of Middlesex county. Budapest is the amalgamation of Buda, Pest and Óbuda. Berlin ( Berlin and Cölln ), in Germany Duisburg ( Duisburg and Hamborn, 1929 -- 1935 called Duisburg - Hamborn ), in North Rhine - Westphalia, Germany Wuppertal ( Barmen and Elberfeld ), in North Rhine - Westphalia, Germany Manchester and the city of Salford, England in the Metropolitan County of Greater Manchester ( formerly in Lancashire ). Stoke - on - Trent was created in 1910 from the towns of Burslem, Hanley, Tunstall, Longton, Fenton and Stoke, taking its name from the latter. Neighbouring Newcastle - under - Lyme remains a separate town. Eindhoven merged with five neighbouring municipalities ( Woensel, Tongelre, Stratum, Gestel en Blaarthem and Strijp ) into the new Groot - Eindhoven ( `` Greater Eindhoven '' ) in 1920. The prefix `` Groot - '' was later dropped. Madrid evolved by absorption of other towns ( like Tetuán de las Victorias, Vallecas, Chamartín de la Rosa or Aravaca ) North america Richmond ( Richmond and Manchester ) in central Virginia Cleveland ( Cleveland and Ohio City ) in Ohio Minneapolis. St. Anthony ( not to be confused with St. Anthony Village, a modern city which is a suburb ) was a twin city to Minneapolis in the two cities ' youth. Minneapolis annexed St. Anthony in the late 1800s. New York City ( five boroughs, historically especially between Manhattan and Brooklyn ) Jersey City, New Jersey, was incorporated in 1820, and slowly grew by annexing surrounding municipalities : Van Vorst Twp. ( 1851 ), Bergen City ( 1869 ), Hudson City ( 1869 ), Bergen Twp. ( 1869 ) and finally Greenville Twp. ( 1873 ). Fremont, California was formed in 1956 by the combination of the five towns of Centerville, Irvington, Niles, Mission San Jose, and Warm Springs, California. The town of Newark has always refused to merge into Fremont, and Newark is completely surrounded by Fremont. What is now the city of Winston - Salem, North Carolina was once two separate towns called Winston and Salem that were combined into one. Ottawa, Ontario, was given its large area by the amalgamation in 2001 of the old City of Ottawa, the suburbs of Nepean, Kanata, Gloucester, Rockcliffe Park, Vanier and Cumberland, Orleans, and the rural townships of West Carleton, Osgoode, Rideau, and Goulbourn Gatineau, Quebec, formed by the amalgamation of the old City of Gatineau, City of Hull, City of Aylmer, City of Buckingham and the Municipality of Masson - Angers all facing the City of Ottawa, Ontario from the north shore of the Ottawa River. Toronto formed by an amalgamation of the Old Toronto with East York, Etobicoke, North York, Scarborough and York, which were themselves products of earlier amalgamations. Thunder Bay, Ontario ( Fort William and Port Arthur ). Lloydminster, Canada, on the Saskatchewan - Alberta border, was formed as a single entity in 1903, when both future provinces were part of the Northwest Territories, but was divided into two separate entities in 1905 because the border between the newly created provinces bisected the community. In 1930, the two towns were reunited as a single town under the shared jurisdiction of both provinces, and Lloydminster was reincorporated as a single city in 1958. Halifax and Dartmouth ( Canada ) were forcibly merged in 1996 along with Bedford and Halifax County to create the Halifax Regional Municipality. Saguenay, Quebec ( Chicoutimi, Jonquière, et al. ) Bellingham, Washington was formed from four cities, Fairhaven, Sehome, Bellingham and Whatcom. Lincoln City, Oregon was formed in 1965 by merging the extant seaside towns of Oceanlake, Delake, and Taft, with the adjoining unincorporated areas of Nelscott and Cutler City. Pittsburgh annexed Allegheny City, which is now the quarter of the city that lies north of the Allegheny and Ohio rivers. Also annexed was Birmingham, now referred to as the `` South Side ''. Bethlehem, Pennsylvania, which absorbed the cities of South Bethlehem, and West Bethlehem. The former Bethlehem and South Bethlehem are situated in Northampton County, and West Bethlehem is in Lehigh County. As a result, present - day Bethlehem straddles the county line. Montreal, Quebec, was merged with the other 27 communities on the Island of Montreal by an act in the Quebec Parliament in 2002. Following a change in the provincial government, several communities later voted via referendum to de-merge and there are now a total of 15, leaving Montreal merged with the other 12. Kingston, Ontario was amalgamated in 1998 with the neighboring Kingston and Pittsburgh Townships. Winnipeg, Manitoba amalgamated with 12 surrounding municipalities and its metropolitan corporation in 1971 under what was referred to as unicity reforms in local government restructuring. Park Hills, Missouri was formed in 1994 by a four - way municipal merger involving the cities of Flat River, Elvins, and Esther, plus the village of Rivermines. Helena - West Helena, Arkansas was formed in 2006 by the merger of the previous cities of Helena and West Helena. Greater Sudbury, Ontario, was formed in 2001 by the amalgamation of the former Regional Municipality of Sudbury, comprising the municipalities of Sudbury, Nickel Centre, Valley East, Capreol, Rayside - Balfour, Onaping Falls and Walden, plus a number of previously unamalgamated townships. The amalgamation made it the most populous city in the Northern Ontario region. Boston, Massachusetts is made up of the former towns of Boston, Dorchester, Brighton, Roxbury, Charlestown, and Hyde Park. Port Alberni, British Columbia was formed in 1967 when Alberni and Port Alberni, merged to become one city. Fictional twin cities Gotham City ( the home of Batman ) and Metropolis ( the home of Superman ) have sometimes been presented as twin cities, mainly in 1970s and 1980s stories by DC Comics. In stories presenting them as twin cities, Gotham City and Metropolis are located on opposite sides of a large bay ( identified as Delaware Bay in 1990 's The Atlas of the DC Universe ), with both cities linked by the Metro - Narrows Bridge, a suspension bridge resembling New York City 's Verrazano - Narrows Bridge. Central City and Keystone City, from the current Flash comics, are shown as twin cities. Before the 1985 - 86 miniseries Crisis on Infinite Earths, Central and Keystone are presented as located in the same space but on different parallel Earths. Their real - life equivalents might possibly be St. Joseph, Missouri and either Elwood or Wathena in Kansas. Ankh - Morpork, from Terry Pratchett 's Discworld novels, is referred to as `` the twin cities of proud Ankh and pestilent Morpork '' Duckburg and St. Canard were depicted in the cartoon Darkwing Duck as sister cities connected by a bridge, very similar to Oakland and San Francisco. See also Divided cities United cities Cross-border town naming Megacity Sister cities List of metropolitan areas that overlap multiple countries List of twin towns and sister cities Global city Ecumenopolis Metropolis Megalopolis Notes Jump up ^ Separated by the North Saskatchewan River. While the communities are commonly referred to by the collective `` The Battlefords, '' they retain distinctive identities. Jump up ^ Main cities of Metropolitan Halifax, they are geographically separated by Halifax Harbour Jump up ^ form the National Capital Region, geopolitically separated by the Ottawa River Jump up ^ See Bloomington -- Normal. Jump up ^ See College Station -- Bryan metropolitan area. Jump up ^ Champaign was originally known as West Urbana but has since outgrown its neighbor. See Champaign -- Urbana metropolitan area. Jump up ^ Twin cores of the Metroplex of northern Texas. Jump up ^ Nicknamed the Twin Ports, these form the world 's largest freshwater port. Jump up ^ Two anchor cities of the three - city Research Triangle area. Jump up ^ See Fargo -- Moorhead. Jump up ^ Largest two cities of the three - city Piedmont Triad area. Jump up ^ Shared international airport named after both cities Greenville -- Spartanburg International Airport. Jump up ^ The principal cities of the Antelope Valley and High Desert in California. Jump up ^ Nicknamed the Petroplex in a nod to the DFW region 's nickname, as well as its strong reliance on the oil industry. Jump up ^ Also known as the Twin Cities Jump up ^ Share the Portland International Jetport ( buildings / terminal in one city, runways in the other ) and the Port of Portland and retain separate identities. Jump up ^ One perhaps more suburban ; see Greater Richmond Region. Jump up ^ The core cities of the Wyoming Valley in northeastern Pennsylvania. Jump up ^ See Sherman -- Denison metropolitan area. Jump up ^ Main cities of the Tampa Bay Area. Jump up ^ the cities meet at the border between Texas and Arkansas, and their name is a portmanteau of those states ' names as well as that of Louisiana, whose border lies approximately 25 miles to the south. See Texarkana metropolitan area and Ark - La - Tex. Jump up ^ Until 1930, the community, divided by the Alberta - Saskatchewan border, was two separate, adjacent towns. However, with the Town of Lloydminster Acts in administration the large town became integrated while still bi-provincial. Jump up ^ Formed historic Al - Mada'in. Jump up ^ Kurashiki is somewhat more of a suburb Jump up ^ Co-centers of a shared major metropolitan area. Jump up ^ Co-centers of a shared micropolitan area. Jump up ^ Co-centers of a shared micropolitan area. Jump up ^ the principal cities of the San Francisco Bay area. References Jump up ^ `` 10 Twin Towns and Sister Cities of Indian States ''. walkthroughindia.com. Retrieved 9 January 2014. ^ Jump up to : `` 10 Twin Towns and Sister Cities of Indian States ''. walkthroughindia.com. Retrieved 9 January 2014. Jump up ^ Weather story from 2006 The Hindu Business Line. Retrieved 2006 - 12 - 31 Jump up ^ ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) Jump up ^ `` It 's a wise man who knows where Chatham ends and Rochester begins. '' Charles Dickens Jump up ^ `` Tricity residents to get Emaar MGF 's Central Plaza soon ''. The Financial Express. Jan 6, 2014. Jump up ^ `` Quad Cities too generic a name for ID, WA cities ''. The Seattle Times. 28 April 2010. Retrieved 22 January 2013. Jump up ^ http://www.grijalvo.com/Madrid/G_Barrios_Madrid_antes_municipios.htm Jump up ^ Action Comics # 451, DC Comics, September 1975 Jump up ^ New Adventures of Superboy # 22, DC Comics, October 1981 Jump up ^ World 's Finest Comics # 259, DC Comics, October -- November 1979 Jump up ^ The Flash ( volume 1 ) # 123, DC Comics, September 1961 Jump up ^ See e.g. the introduction of The Hogfather q : Terry Pratchett 's Hogfather Retrieved from `` https://en.wikipedia.org/w/index.php?title=Twin_cities&oldid=803208261 '' Categories : Twin cities Hidden categories : Articles needing additional references from March 2011 All articles needing additional references Articles with too many examples All articles with unsourced statements Articles with unsourced statements from August 2015 Articles with unsourced statements from September 2014 Talk Contents About Wikipedia Čeština Deutsch Español Esperanto Français 한국어 मराठी 日本 語 Norsk Português Română Slovenčina 文言 中文 Edit links This page was last edited on 1 October 2017, at 03 : 57. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: why do they call them the twin cities
Answer: Twin cities are a special case of two cities or urban centres that are founded in close geographic proximity and then grow into each other over time, losing most of their mutual buffer zone.