El Tajin, Pre-Hispanic City

When Teotihuacan's power faded, El Tajin filled the vacuum, dominating north-eastern Mesoamerica from the early 9th century until the early 13th. Nothing else in the region looks quite like it: columns and friezes crawl with carved reliefs, and the celebrated Pyramid of the Niches encodes astronomical meaning in its stacked, shadow-filled recesses. Hidden in the greenery of Veracruz state, the pre-Hispanic city joined the UNESCO World Heritage List in 1992.