It is one of the most important archaeological sites in the country, the main pyramid has the largest basement in the world, with 400 meters per side, surpassing that of the Sun in Teotihuacán and that of Cheops, in Egypt.
Its name is Tlachihualtepetl, which means handmade hill and on it is the Shrine of Our Lady of Remedies, which was built by the Spaniards in 1594.
Its dome is covered with talavera and inside you can see a neoclassical altar and the virgin, whose devotion was spread by the belief that they appeared to the Spaniards in the sad night.
For their investigation the archaeologists excavated in the construction about 8 km of tunnels that allow the observation of the different phases and today they can be visited.
Within the riches of this site are 2 pre-Hispanic murals, the mural of the drinkers and the mural of the chapulines.
The great pyramid is dedicated to the god Chiconquiahuitl (of the rain) which was revered by the Olmec-Xicalanca culture until 1300 AD