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The world’s third-largest pyramid, surpassed in size only by Egypt’s Cheops and the pyramid of Cholula, overshadows the east side of the Calzada de los Muertos. When Teotihuacán was at its height, the pyramid’s plaster was painted bright red, which must have been a radiant sight at sunset. Clamber (carefully) up the pyramid’s 248 steps – yes, we counted – for an inspiring overview of the ancient city.

The Aztec belief that the structure was dedicated to the sun god was validated in 1971, when archaeologists uncovered a 100m-long underground tunnel leading from the pyramid’s west flank to a cave directly beneath its center, where they found religious artifacts. It’s thought that the sun was worshipped here before the pyramid was built and that the city’s ancient inhabitants traced the origins of life to this grotto.

The pyramid's base is 222m long on each side, and it’s now just over 70m high. The pyramid was cobbled together around AD 100, from three million tonnes of stone, without the use of metal tools, pack animals or the wheel.