Zona Arqueológica de Teotihuacan

The ancient city of Teotihuacan spreads across the valley just east of San Juan Teotihuacan, and it is the reason most people come here. Founded around the turn of the first millennium, it grew into the largest city in the Americas of its time, with a population usually estimated at around 100,000 at its height in the 5th and 6th centuries. Its builders left no readable texts, and even the name is not theirs: Teotihuacan, "the place where the gods were made," is what the Aztecs called the ruins centuries after the city had been abandoned.

The layout is still easy to read. The Avenue of the Dead, a wide ceremonial road several kilometers long, runs from the Pyramid of the Moon in the north past the huge Pyramid of the Sun, one of the largest pyramids ever built, down to the Ciudadela, a sunken plaza around the Temple of the Feathered Serpent with its carved serpent heads. Along the way are palaces and apartment compounds, some with mural paintings that keep their reds and greens.

The city declined in the 6th and 7th centuries, when fire damaged many of the elite buildings along the main avenue. UNESCO listed it as a World Heritage Site in 1987, and it is one of the most visited archaeological sites in Mexico, so it pays to arrive early, before the tour buses and the midday sun.