Teotenango, an important pre-Hispanic fortified city located in the southern part of the Valley of Toluca, existed for about 1000 years, being abandoned only after the Spanish Conquest of Aztecs. In its heyday, the city had a dense population, a main road about 1400 metres long, pyramidal platforms, palaces, a ball game court, formidable defence systems, and drainage and water delivery systems.
The archaeological site has more than forty excavated and at least partially restored monuments. All around the site there are naturally protruding rocks containing petroglyphs (pictographs) with various signs and symbols. However, only a fraction of the site, mostly the north-eastern section which contained the ceremonial centre, has been excavated and preserved. The site is located atop a large hill known as Tetépetl, which is situated just west of the modern town of Tenango de Arista at a height of 2700 metres above sea level.
The name Teotenango is derived from three Nahuatl words: “teotl” (god, sacred, divine or authentic), “tenamitl” (wall, fence or fortification) and “co” (place or in), which lends itself to different translations, such as “in the place of the divine wall”, “in the place of the original fortification” or “in the place of the all of the gods”.
From early pre-Hispanic times, the valley of Toluca was an important settlement area for a number of ethnic groups, whose economic and cultural development was strongly influenced by the natural resources that existed there. Trade routes through the valley brought valued commodities, such as salt, tropical fruits and ocean products like shells.
The Valley of Toluca was also an important gateway to the tropical lowlands to the south and west. After the conquest of the valley by the Aztec Empire it became an important point of control for tribute goods coming to the capital of Tenochtitlan. It was also important as a staging area for the regular wars between the Aztecs and the P’urhépecha (the ingenious tribe).
Teotenango is located in the far southern part of the Valley of Toluca. This area was initially settled and developed during the end years of the Teotihuacán civilisation. The site experienced five periods of occupation and development, extending over 1000 years and ending when the Spanish forced the resettlement of the population to the valley floor below.
Occupation of the area did not begin on Tetepetl Hill, but rather at a location on the valley floor on the north side of the hill. This settlement has been named Ojo de Agua by archaeologists. It was founded by the Otomí people who were joined and strongly influenced by emigrants from the falling Teotihuacán civilisation. These people are now referred to as the Teotenancas. Objects from this part of the site show very strong similarities with objects from Teotihuacán and date from 650 to 750 CE. This is considered to be the first stage of the development of Teotenango. The second stage is dated from 750 to 900 CE. The first constructions of the Teotenango site date from this period, including the temazcal, structures 2C and 3C and some structures that lie under structures in Conjuntos A and C. The reason the settlement moved from the valley floor to the mesa was due to natural defences that the mesa provided. Most of the currently visible structures of the ceremonial centre, such as the pyramidal bases for temples, were built during the third stage (900–1162 CE). Of these constructions, the ball court and the serpent base are the most significant ones. Some residences were also erected. The beginning of the fourth stage (1162-1476) is characterised by the conquest and takeover of the city by the Matlatzincas. They added some small constructions to the ceremonial centre, and amplified some other structures, but are mostly credited with the construction of the city’s massive defence systems, such as the wall on the west side. During that time the city’s population grew significantly, with residential areas spreading toward the south. The fifth and final stage (1474-1550 CE) is characterised by the conquest of Teotenango by the Aztec emperor Axayacatl, and subsequent Aztec occupation of the city and the valley.
Following the excavation of Teotenango, a museum was created to exhibit the recovered artefacts. The museum offers a general overview of the cultural development of the highlands of Mexico, from the first human settlements to the highly stratified societies, which characterised the Postclassic period, with special emphasis on Teotenango.
The Roman Piña Chan Archeological museum, as it is formally called, has three exhibition rooms for its permanent collection, which numbers more than 1000 items. The museum’s largest collection is that of items from the era after the Matlatzinca conquest, including copper utensils, stone tools and sculptures. There are a number of items of an Aztec origin, including sculptures of Xipe Totem and Chicomecoatl, goddesses of fertility. There are also a few pieces from the era of initial contact with the Spaniards. Lastly, the exhibition contains some items from other sites, such as stone tools, clay figures and animal-shaped jars from Tlatilco, a small, very early settlement in the Valley of Mexico.
The abandoned site remained mostly exposed and vaguely known locally since colonial times. It was not until 1969 that archaeologist Banda Tomasi presented a plan to excavate the site. Together with Piña Chan they succeeded in getting five million pesos for investigation, exploration, land purchases and the construction of a site museum.
At that time Román Piña Chan directed a local centre for Instituto Nacional de Antropología e Historia (INAH). He decided to convert Tomasi’s idea into a state project and to gain finance and support from then-governor, Carlos Hank Gonzalez. Since the State of Mexico funded the project, INAH ceded management rights to the state, with the condition that research and security of the site would continue. The project was able to excavate less than half of the two square kilometres of the site, limited to the ceremonial centre concentrated on the northeast of the mesa. Little is known about the residential areas that extend to the south and east. Another area that was left unexcavated was the initial Teotenanca settlement, Ojo de Agua, on the valley floor on the north side of Tetepetl Hill. In the 1970s, using sonar, a small platform was detected about two metres underground and a few objects were uncovered and put on display at the site museum. However, lack of funding prevented any serious work there, but did allow for measures to protect the area from damage, although it still remains private property.
The site consists of five major groupings of buildings called “conjuntos”, and labeled A, B, C, D and E. Conjunto D is more commonly referred to as the Plaza del Serpiente (Plaza of the Serpent). Conjunto E is more commonly referred to as the ball court area. Buildings within each of the conjuntos are denoted with numbers, such as 1A or 1B.
The main entrance to the city is through the plaza of the jaguar, which lies on the hill on the north side just below the level of the rest of the city. From this plaza a series of stone steps takes one up to the city level. The jaguar relief shows a seated jaguar, wearing a medallion around its neck and in the process of eating a kind of flower or heart. To the left of this image there is the representation of the date marker “Two Rabbit” and to the right is the date marker “Nine House”. One of the interpretations of this set of reliefs is that it represents the occurrence of an eclipse. The jaguar represents some kind of earth monster eating the sun, which is represented by the flower or heart figure. An eclipse did indeed occur on the date “Two Rabbit Nine House” on the Aztec calendar. Conjuntos A and B consist of a plaza with a temple pyramid, or rather pyramid base, with one or more smaller buildings associated with it. Both are located at the extreme east of the excavated zone, near where the hill’s steep slopes to the valley floor begin. Conjunto B contains a nearly complete pyramid with a small altar in front and various platforms for dwellings. Some of the structures here show Otomi architectural influence. Buildings here were roofed with thick layers of mud reinforced with poles and had stucco floors, which contain evidence of cooking/heating fires. Conjunto C is a small group of buildings just behind to the west of the jaguar relief and the main stairs entering the city. This area contains some of the oldest exposed structures at the site. The Plaza de la Serpiente (Conjunto D) is located in the western part of the excavated area. The largest structure here is the serpent base, which is 120 metres long and 40 metres wide. The name of the plaza and the building comes from a sculpted stone found at the northeast corner of the serpent base, formed in the shape of a snake’s head. These patios are square and contain drainage system for wastewater. The structure also contains an entrance hallway and pits for fires in the interior. The defensive walls of the city were mostly constructed by the Matlatzincas, who conquered the city in 1200 CE. The largest and most intact are located on the west side of the city. They reach the height of 10 metres and are up to 1.5 metres wide. These were constructed without mortar and took advantage of the contours of the land. The ball court area (Conjunto E) lies to the south of the Plaza de la Serpiente and Conjunto C. The court is sunken and I-shaped, with the top and bottom of the “I” facing east and west. The temazcal, or ritual/purification steam bath is located on the east side of the ball game complex. There is a shallow hole in the centre of the area where rocks would be heated and then sprinkled with water to produce steam. From the centre of the sauna, there is a drainage ditch. Only the sunken foundation remains.