Question: Where were the Aztecs located?

full_context: Document 1: San Pedro Cholula: San Pedro Cholula is a municipality in the Mexican state of Puebla and one of two municipalities which made up the city of Cholula. The city has been divided into two sections since the pre Hispanic era, when revolting Toltec-Chichimecas pushed the formerly dominant Olmec-Xicallanca to the eastern side of the city in the 13th century. The new lords called themselves Cholutecas and built a new temple to Quetzalcoatl on the San Pedro side, which eventually eclipsed the formerly prominent Great Pyramid of Cholula, now on the San Andrés side. When the Spanish arrived in the 16th century, the city of Cholula was an important religious and economic center, but the center of power was on the San Pedro side, centered on what is now the main city plaza and the San Gabriel monastery. The division of the city persisted and San Pedro remained the more dominant, with Spanish families moving onto that side and the rest of the population quickly becoming mestizo. Today, San Pedro is still more commercial and less residential than neighboring San Andrés with most of its population employed in industry, commerce and services rather than agriculture. Although Cholula's main tourist attraction, the Pyramid, is in San Andrés, San Pedro has more tourism infrastructure such as hotels, restaurants and bars.
Document 2: Tapachula: Tapachula de Córdova y Ordóñez, simply known as Tapachula, is a city and municipality located in the far southwest of the state of Chiapas in Mexico, near the Guatemalan border and the Pacific Ocean. It is one of the most important cities of Chiapas economically as the capital of the agriculturally rich Soconusco region as well as port for trade between Mexico and Central America. The area was originally inhabited by the Mames as a region under the control of the Mame state of Xelaju but was first established as a city by the Aztecs in the 13th century. Most of its economic importance has come since the late 19th century with the establishment of coffee plantations. This agricultural production began a history of migration into the area which continues to this day and has left the city with a significant Asian and German cultural presence as well as large Mayan and Nahua indigenous populations.
Document 3: Geography of Mexico: The geography of Mexico describes the geographic features of Mexico, a country in the Americas. Mexico is located at about 23° N and 102° W in the southern portion of North America. From its farthest land points, Mexico is a little over 3,200 km in length. Mexico is bounded to the north by the United States (specifically, from west to east, by California, Arizona, New Mexico, and Texas), to the west and south by the Pacific Ocean, to the east by the Gulf of Mexico, and to the southeast by Belize, Guatemala, and the Caribbean Sea. The northernmost constituent of Latin America, it is the most populous Spanish-speaking country in the world. Mexico is the world's 13th largest country, three times the size of Texas.
Document 4: Venustiano Carranza, Mexico City: Venustiano Carranza is one of the 16 municipalities of Mexico City. The borough was formed in 1970 when the center of Mexico City was subdivided into four boroughs. Venustiano Carranza extends from the far eastern portion of the historic center of Mexico City eastward to the Peñón de los Baños and the border dividing the then Federal District from the State of Mexico. Historically, most of the territory was under Lake Texcoco, but over the colonial period into the 20th century, the lake dried up and today the area is completely urbanized. The borough is home to three of Mexico City's major traditional markets, including La Merced, the National Archives of Mexico, the Palacio Legislativo de San Lázaro, the TAPO intercity bus terminal and the Mexico City Airport.
Document 5: Teotihuacan: Teotihuacan , also written Teotihuacán (] ,    ), is an ancient Mesoamerican city located in a sub-valley of the Valley of Mexico, located in the State of Mexico 40 km northeast of modern-day Mexico City, known today as the site of many of the most architecturally significant Mesoamerican pyramids built in the pre-Columbian Americas.
Document 6: Mezquital Valley: The Mezquital Valley (Otomi: B’ot’ähi) is a series of small valleys and flat areas located in Central Mexico, about 60 km north of Mexico City, located in the western part of the state of Hidalgo. It is part of the central Mexican highlands, with altitudes between 1,700 m and 2,100 m above sea level. It is one of Mexico's main semi-arid/area regions, whose native vegetation is dominated by cactus species, mesquite trees, and maguey with pine and oak trees in the highest elevations. It is considered to be part of the northern extension of Mesoamerica, with one major archeological site, Tula, which was the main city of the Toltecs, an important influence for the later Aztecs, this area was on two important Aztec tribute regions, Teotlalpan and Jilotepec Province. However, from the Aztec period to the 20th century, it was sparsely populated and very poor, with one main indigenous ethnicity, the Otomis. In the 20th century, irrigation works were created to take advantage of the water in the Tula River, along with wastewater drained from the Valley of Mexico for agriculture. Today the valley produces various grains and produce, including one-quarter of all green chili peppers grown in Mexico.
Document 7: Greater Mexico City: Greater Mexico City refers to the conurbation around Mexico City, officially called Valley of Mexico Metropolitan Area ("Zona Metropolitana del Valle de México"), constituted by Mexico City itself composed of 16 Municipalities—and 41 adjacent municipalities of the states of Mexico and Hidalgo. For normative purposes, however, Greater Mexico City most commonly refers to the Metropolitan Area of the Valley of Mexico ("Zona Metropolitana del Valle de México") an agglomeration that incorporates 18 additional municipalities. As of 2010 Census, Greater Mexico City had a population just over 20 million, making it the largest metropolitan area in North America just ahead of the New York metropolitan area. But as of a 2014 census, it's estimated the population of Greater Mexico City was 25.4 million people, making it the largest urban agglomeration in the western hemisphere. It is surrounded by thin strips of highlands which separate it from other adjacent metropolitan areas, of which the biggest are Puebla, Toluca, and Cuernavaca-Cuautla, and together with which it makes up the Mexico City megalopolis.
Document 8: Costa Grande of Guerrero: Costa Grande of Guerrero is a sociopolitical region located in the Mexican state of Guerrero, along the Pacific Coast. It makes up 325 km of Guerrero’s approximately 500 km coastline, extending from the Michoacán border to the Acapulco area, wedged between the Sierra Madre del Sur and the Pacific Ocean. Acapulco is often considered part of the Costa Grande; however, the government of the state classifies the area around the city as a separate region. The Costa Grande roughly correlates to the Cihuatlán province of the Aztec Empire, which was conquered between 1497 and 1504. Before, this much of the area belonged to a dominion under the control of the Cuitlatecs, but efforts by both the Purépecha Empire and Aztec Empire to expand into this area in the 15th century brought this to an end. Before the colonial period, the area had always been sparsely populated with widely dispersed settlements. The arrival of the Aztecs caused many to flee and the later arrival of the Spanish had the same effect. For this reason, there are few archeological remains; however, recent work especially at La Soledad de Maciel has indicated that the cultures here are more important than previously thought. Today, the area economically is heavily dependent on agriculture, livestock, fishing and forestry, with only Zihuatanejo and Ixtapa with significantly developed infrastructure for tourism. The rest of the coast has been developed spottily, despite some government efforts to promote the area.
Document 9: Chichen Itza: Chichen Itza ( , Spanish: "Chichén Itzá" ] , often with the emphasis reversed in English to ; from Yucatec Maya: "Chi<nowiki>'</nowiki>ch<nowiki>'</nowiki>èen Ìitsha<nowiki>'</nowiki>" ] "at the mouth of the well of the Itza people") was a large pre-Columbian city built by the Maya people of the Terminal Classic period. The archaeological site is located in Tinúm Municipality, Yucatán State, Mexico.
Document 10: Maya calendar: The Maya calendar is a system of calendars used in pre-Columbian Mesoamerica and in many modern communities in the Guatemalan highlands, Veracruz, Oaxaca and Chiapas, Mexico.
Document 11: Tizatlan: Tizatlan, in pre-Columbian Mexico, was one of the four independent altepemeh (polities, sing. altepetl) that constituted the confederation of Tlaxcallan. Today Tizatlan is a part of the modern city of Tlaxcala, and the Pre-Columbian city is visible as a small archaeological site. The site is in the state of Tlaxcala in central Mexico.
Document 12: Geography of Mesoamerica: The geography of Mesoamerica describes the geographic features of Mesoamerica, a culture area in the Americas inhabited by complex indigenous pre-Columbian cultures exhibiting a suite of shared and common cultural characteristics. Several well-known Mesoamerican cultures include the Olmec, Teotihuacan, the Maya, the Aztec and the Purépecha. Mesoamerica is often subdivided in a number of ways. One common method, albeit a broad and general classification, is to distinguish between the highlands and lowlands. Another way is to subdivide the region into sub-areas that generally correlate to either culture areas or specific physiographic regions.
Document 13: Texcoco, State of Mexico: Texcoco (   ) is a city and municipality located in the State of Mexico, 25 km northeast of Mexico City. In the pre-Hispanic era, this was a major Aztec city on the shores of Lake Texcoco. After the Conquest, the city was initially the second most important after Mexico City, but its importance faded over time, becoming more rural in character. Over the colonial and post-independence periods, most of Lake Texcoco was drained and the city is no longer on the shore and much of the municipality is on lakebed. Numerous Aztec archeological finds have been discovered here, including the 125 tonne stone statue of Tlaloc, which now resides at the Museum of Anthropology in Mexico City.
Document 14: Zapotec civilization: The Zapotec civilization was an indigenous pre-Columbian civilization that flourished in the Valley of Oaxaca in Mesoamerica. Archaeological evidence shows that their culture goes back at least 2,500 years. The Zapotec left archaeological evidence at the ancient city of Monte Albán in the form of buildings, ball courts, magnificent tombs and grave goods including finely worked gold jewelry. Monte Albán was one of the first major cities in Mesoamerica and the center of a Zapotec state that dominated much of the territory that today belongs to the Mexican state of Oaxaca.
Document 15: Mexico City: Mexico City, or the City of Mexico (Spanish: "Ciudad de México" , ] ; abbreviated as CDMX), is the capital and most populous city of Mexico. Mexico City is one of the most important financial centers in the Americas. It is located in the Valley of Mexico ("Valle de México"), a large valley in the high plateaus at the center of Mexico, at an altitude of 2240 m . The city consists of sixteen municipalities.
ground_truth: a sub-valley of the Valley of Mexico