Cholula Archeological Zone is in the center of town off Calzada San Andres Cholula to Av. 14 Poniente, near the main square. It is completely dominated by the Great Pyramid of Tepanapa (officially, the tongue-twisting Tlachihualtepetl), a massive structure that has a base length of about 1,315 feet—each side is some 500 feet longer than the Pyramid of the Sun at Teotihuacán. This is one of the three largest pyramids in the world by total volume.
Looking more like a wide hill than a traditional pyramidal structure, it was built around 100 B.C. By the time Hernando Cortés arrived in Cholula in 1519, temples built by the Toltecs and later the Aztecs surrounded the Great Pyramid, and it escaped the destructive wrath the Spanish conqueror unleashed on the buildings around it.
Hike up the stone trail to the top and the Santuario de Nuestra Señora de los Remedios (Sanctuary of Our Lady of Remedies), which crowns the hill 217 feet above ground level. This lovely parish church, built in the late 16th century, has twin domes adorned with mosaic tiles and a breathtaking interior replete with gold-leaf ornamentation. The view of the city and surrounding countryside from the pyramid's summit is well worth the climb.
Archeological excavations undertaken in the 1930s to study the pyramid created some 5 miles of zigzagging subterranean passageways that reveal various stages of construction over centuries. The passageways open to visitors feature models of the pyramid built into the walls. You'll also catch glimpses of narrow stairways and ancient chambers.
The site museum, near the entrance, has a cutaway view of the pyramid showing its different levels and displays pre-Hispanic artifacts, knives and arrowheads. Vendors set up booths under the trees behind the pyramid, selling handicrafts and homemade sweets, and a team of voladores (“flying men”) regularly performs the dramatic and dangerous flying pole dance for tourists. Freelance tour guides, who congregate at the entrance, will identify various structures and point out decorative highlights.