Technically in Tlalnepantla de Baz, in the State of Mexico, the site is what remains of a fortified city, mostly from the late 1200s and built likely by Hñañu and Otomí, often referred to as Chichimeca, a perjorative Nahuatl term. There are remains indicating that the site was occupied as early as the Classic Period. But the population increased in the early Post-classic and continued to expand after the fall of Tula, when Tenayuca is thought to have became a significant regional power.
Like lots of other temple sites, Tenayuca represents multiple construction phases built one atop another. All of the serpent sculptures on the site are associated with fire and sun worship. 200 meters from the main pyramid are the remains of an elite residential complex, with some surviving plaster floors in some rooms.
The entrance fee to the grounds is 55 pesos.
Hours: Tuesday through Sunday, 10 a.m. to 5 p.m.