Edo Castle , also known as , is a flatland castle that was built in 1457 by Ōta Dōkan . It is located in Chiyoda in Tokyo , then known as Edo , Toshima District , Musashi Province . Tokugawa Ieyasu established the Tokugawa shogunate here . It was the residence of the shogun and location of the shogunate , and also functioned as the military capital during the Edo period of Japanese history . After the vacation of the shogun and the Meiji Restoration , it became the Tokyo Imperial Palace . Some moat s , walls and ramparts of the castle survive to this day . However , the grounds were more extensive during the Edo period , with Tokyo Station and the Marunouchi section of the city lying within the outermost moat . It also encompassed Kitanomaru Park , the Nippon Budokan Hall and other landmarks of the surrounding area . History . The warrior Edo Shigetsugu built his residence in what is now the " Honmaru " and " Ninomaru " part of Edo Castle , around the end of the Heian or the beginning of the Kamakura period . The Edo clan perished in the 15th century as a result of uprisings in the Kantō region , and Ōta Dōkan , a retainer of the Ogigayatsu Uesugi family , built Edo Castle in 1457 . The castle later came under the control by the Late Hōjō clan . The castle was vacated in 1590 due to the Siege of Odawara . Tokugawa Ieyasu made Edo Castle his base after he was offered eight eastern provinces by Toyotomi Hideyoshi . He later defeated Toyotomi Hideyori , son of Hideyoshi , at the Siege of Osaka in 1615 , and emerged as the political leader of Japan . Tokugawa Ieyasu received the title of Seii Taishōgun in 1603 , and Edo became the center of Tokugawa ' s administration . Initially , parts of the uninhabitable area were lying under water . The sea reached the later " Nishinomaru " area of Edo Castle , and Hibiya was a beach . The land was changed for the construction of the castle . Most construction started in 1593 and completed in 1636 under the grandson Tokugawa Iemitsu . By this time , Edo had a population of 150 , 000 . The grounds extended with the addition of " Nishinomaru " , " Nishinomaru - shita " , " Fukiage " , and " Kitanomaru " areas to the existing " Honmaru " , " Ninomaru " , and " Sannomaru " areas . The perimeter measured 16 km . The daimyō were required by the shōgun to supply building materials or finances , a method used by the shogunate to keep the powers of the daimyo in check . Large granite stones were moved from afar , the size and number of the stones depend on the wealth of the daimyo . The wealthier ones had to contribute more . Those who did not supply stones were required to contribute labor in tasks , such as digging the large moats and flattening hills . The earth that was taken from the moats were used as landfill for sea - reclamation or to level the ground . Thus the construction of Edo Castle laid the foundation for parts of the city where merchants were able to settle . At least 10 , 000 men were involved in the first phase of the construction and more than 300 , 000 in the middle phase . When construction ended , the castle had 38 gates . The ramparts were almost 20 meters and the outer walls were 12 meters high . Moats that were throughout the rough concentric circles were dug for further protection . Some moats reached as far as Ichigaya and Yotsuya areas , and parts of the ramparts survived to this day . This area is surrounded by either the sea or the Kanda river , and therefore allow ships to navigate . Various fires over the centuries damaged or destroyed parts of the castle . Edo and the majority of the buildings were constructed out of wood . On April 21 , 1701 , in the Great Pine Corridor ( " Matsu no Ōrōka " ) of Edo Castle , Asano Takumi - no - kami drew his short sword and attempted to kill Kira Kōzuke - no - suke for insulting him . This triggered the events involving the Forty - seven Ronin . After the capitulation of the shogunate in 1867 , the inhabitants including the shogun had to vacate the premises . The castle compound was renamed in October , 1868 , and then renamed in 1869 . In the year Meiji 2 ( 1868 ) , on the day 23 of the 10th month , the emperor moved to Tokyo and Edo castle became an imperial palace . A fire consumed the old Edo Castle on the night of May 5 , 1873 . The area around the old donjon , which burned in the 1657 Meireki fire , became the site of the new imperial built in 1888 . Some Tokugawa era buildings which were still standing were destroyed to make space for new structures for the imperial government . The imperial palace building itself , however , was not constructed on the same location as the shogun ' s palace , which was located in the " Honmaru " , but in the " Nishinomaru " enceinte . The site suffered substantial damage during World War II , and the destruction of Tokyo , in 1945 . Today the site is part of the Tokyo Imperial Palace . The government declared the area an historic site and has undertaken steps to restore and preserve the remaining structures of Edo Castle . Appearance of Edo Castle . The plan of Edo Castle was not only large but elaborate . The grounds were divided into various enceinte s , or citadels . The " Honmaru " was in the center , with the " Ninomaru " ( second compound ) , " Sannomaru " ( third compound ) extending to the east ; the " Nishinomaru " ( west compound ) flanked by " Nishinomaru - shita " ( outer section ) and " Fukiage " ( firebreak compound ) ; and the " Kitanomaru " ( north compound ) . The different enceintes were divided by moats and large stone walls , on which were various keeps , defense houses and towers were built . To the east , beyond the " Sannomaru " was an outer moat , enclosing the " Otomachi " and " Daimyo - Koji " districts . " Ishigaki " stone walls were constructed around the " Honmaru " and the eastern side of the " Nishinomaru " . Each enceinte could be reached via wooden bridges , which were buffered by gates on either side . The circumference is subject to debate , with estimates ranging from 6 to 10 miles . With the enforcement of the " sankin - kōtai " system in the 17th century , it became expedient for the various daimyo to set up residence in Edo in close proximity to the shogun . Surrounding the inner compounds of the castle were the residences of various daimyo , most of which were concentrated at the Outer Sakurada Gate to the south - east and in the " Ōtemachi " and " Daimyo - Kōji " districts east of the castle inside the outer moat . Some residences were also located within the inner moats in the outer " Nishinomaru " . The mansions were very elaborate and large , with no expenses spared to construct palaces with Japanese gardens and multiple gates . Each block had four to six of the mansions , which were surrounded by ditches for drainage . Daimyo with lesser wealth were allowed to set up their houses , called " bancho " , to the north and west of the castle . To the east and south of the castle were sections that were set aside for merchants , since this area was considered unsuitable for residences . The entertainment district Yoshiwara was also located here . Gates . The inner citadels of the castle were protected by multiple large and small wooden gates ( " mon " ) , constructed in - between the gaps of the stone wall . Not many are left today . From south to southwest to north , the main gates are located at " Nijūbashi " , " Sakurada - mon " , " Sakashita - mon " , " Kikyō - mon " , " Hanzō - mon " , " Inui - mon " , " Ōte - mon " , " Hirakawa - mon " and " Kitahanebashi - mon " . Only the stone foundations of the other gates ( meaning the gap left in between the large stone walls for the wooden gates ) are still preserved . Large gates , such as the " Ōte - mon " , had a guard of 120 men , while the smaller gates were guarded by 30 to 70 armed men . An eye - witness account is given by the French director François Caron from the Dutch colony at Dejima . He described the gates and courts being laid out in such a manner as to confuse an outsider . Caron noted the gates were not placed in a straight line , but were staggered , forcing a person to make a 90 degree turn to pass on to the next gate . This style of construction for the main gates is called " masugata " ( meaning " square " ) . As noted by Caron , the gate consisted of a square - shaped courtyard or enclosure and a two story gatehouse which is entered via three roofed " kōrai - mon " . The " watari - yagura - mon " was constructed at adjacent angles to each side within the gate . All major gates had large timbers that framed the main entry point and were constructed to impress and proclaim the might of the shogunate . Garrison . Accounts of how many armed men served at Edo Castle vary . The Spanish Governor - General of the Philippines Rodrigo de Vivero y Velasco gave an eye - witness account in 1608 – 1609 , describing the huge stones that made up the walls and a large number of people at the castle . He claimed to have seen 20 , 000 servants between the first gate and the shogun ' s palace . He passed through two ranks of 1 , 000 soldiers armed with musket s , and by the second gate he was escorted by 400 armed men . He passed stables that apparently had room for 200 horses and an armory that stored enough weapons for 100 , 000 men . " Honmaru " . The " Honmaru " ( 本丸 ) ( also spelled " Hommaru " ) was the central , innermost part of the castle containing the donjon and residence of the shogun . The stately and luxurious main buildings of the " Honmaru " , consisting of the outer , central , and inner halls , were said to have covered an area of 33 , 000 square meters during the Kan - ei era ( 1624 – 1644 ) . Surrounding the " Honmaru " were curtain walls , with 11 keeps , 15 defense houses and more than 20 gates . " Honmaru " was destroyed several times by fire and reconstructed after each fire . The donjon and main palace were destroyed in 1657 and 1863 , respectively , and not reconstructed . Some remains , such as the " Fujimi - yagura " keep and " Fujimi - tamon " defense house , still exist . The " Honmaru " was surrounded by moats on all sides . To the north separating " Honmaru " from the " Kitanomaru " were the " Inui - bori " and " Hirakawa - bori " , to the east separating the " Ninomaru " was the " Hakuchō - bori " , and to the west and south separating the " Nishinomaru " were the " Hasuike - bori " and " Hamaguri - bori " . Most of these still exist , although the " Hakuchō - bori " has partly been filled in since the Meiji era . " Kitahanebashi - mon " . is the northern gate to the " Honmaru " enceinte , facing " Kitanomaru " enceinte across Daikan - cho street . It is also constructed as a " masu " - gate just like " Ōte - mon " and " Hirakawa - mon " , and has a " watari - yagura - mon " in a left angle . The bridge in front of the gate , which was once a drawbridge during the Edo period , is now fixed to the ground . The metal clasps used to draw the bridge are still attached to the roof of the gate . Donjon . The main donjon or tower ( known as the ) was located in the northern corner of the " Honmaru " enceinte . " Kitahanebashi - mon " is located right next to it and was one of the main gateways to this innermost part . The measurements are 41 meters in width from east to west , 45 meters in length from north to south , and 11 meters in height . A five - storey donjon used to stand on this base which was 51 meters in height and was thus the highest castle tower in the whole of Japan , symbolizing the power of the shogun . The donjon and its multiple roofs were constructed in 1607 and ornamented with gold . It was destroyed in the 1657 Fire of Meireki and not reconstructed . The foundations of the donjon are all that is left . Despite this , " jidaigeki " movies ( such as Abarembo shogun ) set in Edo usually depict Edo Castle as having a donjon , and substitute Himeji Castle for that purpose . A non - profit " Rebuilding Edo - jo Association " ( NPO江戸城再建 ) was founded in 2004 with the aim of a historically correct reconstruction of at least the main donjon . In March 2013 Naotaka Kotake , head of the group , said that " The capital city needs a symbolic building , " and that the group planned to collect donations and signatures on a petition in the hope of having the tower rebuilt . A reconstruction blueprint had been made based on old documents . The Imperial Household Agency had not indicated whether it would support the project . " Honmaru " Palace . The residential and the gardens of the shogun and his court were constructed around the castle keep in the " Honmaru " area . It consisted a series of low - level buildings , connected by corridors and congregating around various gardens , courtyards or lying detached , similar to the structures that can be seen in Nijo Castle in Kyoto today . These structures were used for either residential or governmental purposes such as audiences . The " Honmaru " Palace was one story high , and consisted of three sections : Various fires destroyed the " Honmaru " Palace over time and was rebuilt after each fire . In the span from 1844 to 1863 , " Honmaru " experienced three fires . After each fire , the shogun moved to the " Nishinomaru " residences for the time being until reconstruction was complete . However , in 1853 both the " Honmaru " and " Nishinomaru " burned down , forcing the shogun to move into a daimyo residence . The last fire occurred in 1873 , after which the palace was not rebuilt by the new imperial government . Located behind the " Honmaru " Palace was the main donjon . Besides being the location of the donjon and palace , the " Honmaru " was also the site of the treasury . Three storehouses that bordered on a rampart adjoined the palace on the other side . The entrance was small , made with thick lumber and heavily guarded . Behind the wall was a deep drop to the moat below , making the area secure . " Fujimi - yagura " . The stands in the south - eastern corner of the " Honmaru " enceinte and is three storeys high . " Fujimi - yagura " is one of only three remaining keeps of the inner citadel of Edo Castle , from a total number of originally eleven . The other remaining keeps are " Fushimi - yagura " ( located next to the upper steel bridge of " Nijūbashi " ) and " Tatsumi - nijyu - yagura " ( at the corner of " Kikyō - bori " moat next to " Kikyō - mon " gate ) . It is also called the " all - front - sided " keep because all sides look the same from all directions . It is believed that once Mount Fuji could be seen from this keep , hence the name . Since the main donjon of Edo Castle was destroyed in 1657 and not reconstructed , the " Fujimi - yagura " took on its role and was an important building during the Edo period . About 150 – 160 meters north of the " Fujimi - yagura " is the former site of the " Matsu no Ōrōka " corridor , scene of dramatic events in 1701 that led to the Forty - seven Ronin incident . " Fujimi - tamon " . The defense house is located about 120 – 130 meters north from the " Matsu no Ōrōka " . This defense house sits on top of the large stone walls overlooking to the " Hasuike - bori " ( Lotus - growing moat ) . Weapons and tools were stored here . During the Edo period , double and triple keeps ( " yagura " ) were constructed at strategic points on top of the stone wall surrounding the " Honmaru " . In between each keep , a defense house ( called " tamon " ) was erected for defensive purposes . There were once 15 of these houses in the " Honmaru " , of which only the " Fujimi - tamon " still exists . " Ishimuro " . North of the " Fujimi - tamon " is the , located on a slope . It is about 20 square meters . Its precise purpose is unknown , but since it is located close to the former inner palace storage area , it is believed to have been used for storage of supplies and documents for the shogunate . " Shiomi - zaka " . is a slope running alongside today ' s Imperial Music Department building towards " Ninomaru " enceinte . In old times apparently the sea could be seen from here , therefore its name . " Ninomaru " . At the foot of the " Shiomi - zaka " on the eastern side of the " Honmaru " lies the of Edo Castle . A palace for the heirs of the Tokugawa shoguns was constructed in 1639 in the west area and in 1630 it is reported that a garden designed by Kobori Enshu , who was the founder of Japanese landscaping , was located to its south - east . Several fires destroyed whatever stood here and it was not reconstructed . Aside from the " Honmaru " palace , the " Ninomaru " was surrounded by 7 keeps , 8 defense houses , approximately 10 gates and other guardhouses . The " Tenjin - bori " separates a part of the " Ninomaru " to the " Sannomaru " . Several renovations were carried out over the years until the Meiji era . A completely new garden has been laid out since then around the old pond left from the Edo period . Only the " Hyakunin - bansho " and " Dōshin - bansho " are still standing . " Dōshin - bansho " . The is a guardhouse . A big guardhouse was located within the " Ōte - mon " where today ’ s security is located . The passageway proceeding west from the guardhouse becomes narrower within the stone walls on both sides . The " dōshin - bansho " is located on the right side past this passageway . This is where the samurai guardsmen were posted to watch over the castle grounds . " Hyakunin - bansho " . There is a big stone wall in front of the " Dōshin - bansho " , which is the foundation of the " Ōte - sanno - mon watari - yagura " keep . The long building to the left on the southern side of this foundation is the . The " Hyakunin - bansho " is so - called because it housed hundred guardsmen closely associated with the Tokugawa clan . " Ō - bansho " . The large stone wall in front of the " Hyakunin - bansho " is all that is left of the " Naka - no - mon watari - yagura " ( Inner Gate Keep ) . This building to the inner - right side of the gate is the . As the " Honmaru " enceinte was said to begin right behind the " Naka - no - mon " gate , the " Ō - bansho " probably played a key role in the security of Edo Castle . " Suwa - no - Chaya " . The is a teahouse that was once located in the " Fukiage " garden during the Edo period . After various relocations in the Meiji era , today it is located in the modern " Ninomaru " Garden . " Sannomaru " . The is the eastern most enceinte next to the " Ninomaru " , separated by the " Tenjin - bori " . Ōte - bori is located to the north , running then south is " Kikyō - bori " . " Bairin - zaka " . A steep slope , , runs from eastern " Honmaru " toward " Hirakawa - mon " in front of the today ' s Archives and Mausolea Department building . It is said that Ota Dokan planted several hundred plum trees in 1478 in dedication to Sugawara - no - Michizane . Dokan is said to have built the Sanno - Gongendo here , where two shrines were located when the Tokugawa clan occupied the site . With the erection of the " Honmaru " of Edo Castle , the shrine dedicated to Sugawara - no - Michizane was moved to Kojimachi Hirakawa - cho and later became known as Hirakawa Shrine . The Sanno Shrine was first moved to " Momijiyama " of Edo Castle and became its tutelary shrine but was moved again . Today it is known as Hie Shrine . " Hirakawa - mon " . is said to have been the main gate to the " Sannomaru " of Edo Castle . It is also said to have been the side gate for maidservants and therefore called the " Otsubone - mon " . The shape of this gate is in the " masugata " , similar to the " Ōte - mon " . However a " watari - yagura - mon " is built to an adjacent left angle within the " kōrai - mon " , of which it has two . The other " kōrai - mon " is located to the west of the " watari - yagura - mon " which was used as the " gates of the unclean " for the deceased and criminals from within the castle . Outside this gate is a wooden bridge with railings crowned with " giboshi " - ornamental tops . " Ōte - mon " . was the main gate of the castle . During the reign of the second shogun Tokugawa Hidetada , the castle underwent repairs in the 1620s and the gate is said to have taken its present form at this time , with the help of Date Masamune , lord of Sendai Castle , and Soma Toshitane , lord of Nakamura Castle . A fire in Edo destroyed the " Ōte - mon " in January 1657 , but was reconstructed in November 1658 . It was severely damaged twice , in 1703 and 1855 , by strong earthquakes , and reconstructed to stand until the Meiji era . Several repairs were conducted after the Meiji era , but the damage caused by the September 1923 Great Kantō earthquake lead to the dismantling of the " watari - yagura " and rebuilding of the stone walls on each side of the gate in 1925 . The " watari - yagura " was burnt down completely during World War II on April 30 , 1945 . Restoration took place from October 1965 through March 1967 , to repair the " kōrai " - mon and its walls , and the " Ōte - mon " was reconstructed . " Tatsumi - yagura " . The , also known as , is a two - storey high keep at the easternmost corner of the " Sannomaru " and the only keep still remaining in it . " Kikyō - mon " . One of the few gates left of the " Ninomaru " is the , which is also known as the Inner " Sakurada - mon " , as opposed to the ( Outer ) " Sakurada - mon " in the south . The architecture of the tower is a gate and in the " kōrai " style . " Nishinomaru " . The was the location of the palaces and residences of the retired shogun and the heir - apparent for a while . The outer part of the " Nishinomaru " to the east ( today ' s Outer Gardens of the Imperial Palace ) was the site of various residences of daimyo . The " Nishinomaru " is bordered by moats to the west such as the " Dōkan - bori " , " Sakurada - bori " and Gaisen - bori to the south , " Kikyō - bori " and " Hamaguri - bori " to the north . After each fire in the " Honmaru " , the shogun normally moved into the " Nishinomaru " , although it was also destroyed by fire in 1853 . On May 5 , 1873 , the " Nishinomaru " residence burned down . On its site , the imperial palace was built in the Meiji era . " Sakurada - mon " . Protecting the " Nishinomaru " from the south is the large Outer . This gate is not to be confused with the Inner " Sakurada - mon " , also known as " Kikyo - mon " between " Nishinomaru " and " Sannomaru " . " Seimon Ishibashi " and " Seimon Tetsubashi " . Two bridges led over the moats . The bridges that were once wooden and arched , were replaced with modern stone and iron cast structures in the Meiji era . The bridges were once buffered by gates on both ends , of which only the " Nishinomaru " - mon has survived , which is the main gate to today ' s Imperial Palace . The bridge in the foreground used to be called , while the one in the back was called . After their replacement in the Meiji era , the bridge is now called ) and , respectively . The iron bridge is also known as , because the original wooden bridge was built on top of an auxiliary bridge due to the deepness of the moat . The stone bridge is also called because of its shape . However , both bridges are often mistakenly collectively called Nijūbashi . Today both bridges are closed to the public except on January 2 and the Emperor ' s birthday . " Fushimi - yagura " . is a two - storey keep that still exists at the western corner leading towards the inner " Nishinomaru " , flanked by two galleries ( " tamon " ) on each side . It is the only keep that is left in the " Nishinomaru " . It comes originally from Fushimi Castle in Kyoto . " Sakashita - mon " . originally faced the north , but was changed to face the east in the Meiji era . This tower gate overlooks " Hamaguri - bori " . The assassination of Nobumasa Ando , a member of the shogun ' s Council of Elders , occurred outside this gate . " Momijiyama " . is an area in northern " Nishinomaru " . The area had shrines dedicated to former shoguns in which ceremonies were conducted in memory of them and were held regularly . Tokugawa Ieyasu built a library in 1602 within the Fujimi bower of the castle with many books he obtained from an old library in Kanazawa . In July 1693 , a new library was constructed at " Momijiyama " ( " Momijiyama Bunko " ) . The so - called " Momijiyama Bunkobon " are the books from that library , which are preserved in the National Archives of Japan today . This group consists chiefly of books published during the Song dynasty , Korean books that were formerly in the possession of the Kanazawa Bunko library , books presented by the Hayashi family as gifts , and fair copies of books compiled by the Tokugawa government . " Fukiage " . The is the western area that was made into a firebreak after the great Meireki fire of 1657 . The " Fukiage " is encircled by the " Dōkan - bori " to the " Nishinomaru " to the east , the " Sakurada - bori " to the south , the " Hanzō - bori " to the west , the " Chidorigafuchi " to the northwest and the " Inui - bori " to the north . " Inui - mon " . The was located in the " Nishinomaru " area next to today ' s headquarters of the Imperial Household Agency and called " Nishinomaru Ura - mon " . It was relocated to its present location between the " Kitanomaru " and " Fukiage " garden in the Meiji era . It has its name because of its location in the northwestern part of the Imperial Palace grounds . " Hanzōmon " . The is a gate in the " kōrai " style . The old gate was destroyed by fire during World War II . The Wadakura Gate was moved here in its stead . The " Hanzō - mon " is the only gate to the " Fukiage " area from outside today . " Kitanomaru " . The is the northern enceinte next to the " Honmaru " . It was used as a medicinal garden ( " Ohanabatake " ) during the shogun ' s rule . During the 17th century , the Suruga Dainagon residence was located there as well , which was used by collateral branches of the Tokugawa clan . Today this site is the location of the public Kitanomaru Park . Not much is left from the times of the Edo Castle except for two gates , " Shimizu - mon " and further north " Tayasu - mon " . " Kitanomaru " is surrounded by moats . The " Inui - bori " and " Hirakawa - bori " to the south separate it from the " Honmaru " and " Chidorigafuchi " to the west . Modern Tokyo . Many place names in Tokyo derive from Edo Castle . Ōtemachi ( " the town in front of the great gate " ) , Takebashi ( " the Bamboo Bridge " ) , Toranomon ( " the Tiger Gate " ) , Uchibori Dōri ( " Inner Moat Street " ) , Sotobori Dōri ( " Outer Moat Street " ) , and Marunouchi ( " Within the enclosure " ) are examples .