What looks like a hill with a church on top is actually the largest pyramid in the world by volume. The Great Pyramid of Cholula, known as Tlachihualtepetl, was built in several stages over many centuries before the Spanish conquest, and it is so overgrown with grass and trees that the Spanish took it for a natural hill and built the church of Nuestra Señora de los Remedios on its summit. Today you can walk through tunnels excavated inside it and climb to the church, from where, on a clear morning, the snow-capped cone of Popocatépetl rises behind the yellow walls.
Cholula was one of the great religious centres of central Mexico, a city of temples and pilgrims long before the Aztecs. In 1519 Hernán Cortés and his army massacred thousands of its people on their way to Tenochtitlan, and the Spanish then built churches on the ruins of the temples. Local legend says there is a church for every day of the year, and while that is an exaggeration, the domes and bell towers of dozens of churches rise above the town and the surrounding villages.
Today Cholula, with nearly ninety thousand people, is almost part of the city of Puebla, with a large university and a lively student scene. The centre has a big zócalo, arcades, cafes and restaurants, and it is a pleasant place to spend an evening. Puebla, a few kilometres east, is famous for its colonial architecture, Talavera pottery and food, including mole poblano and chiles en nogada.
For riders on the Popocatépetl Monastery Route, Cholula is a natural starting point. The roads south and west toward Atlixco and the slopes of the volcano climb through farmland and villages with views of Popocatépetl and Iztaccíhuatl. The traffic around Puebla and Cholula is heavy and chaotic, with buses, taxis and topes, so allow time to escape it. Cholula has plenty of fuel, food and accommodation.
Popocatépetl is an active volcano, and it sometimes sends up plumes of ash, which can fall on the surrounding area. Check the current alert level before heading up the volcano's slopes. The dry season, from November to May, offers the clearest views.