Tiwanaku

Tiwanaku is the ruined ceremonial and urban center of a pre-Inca civilization that flourished on the Bolivian altiplano near Lake Titicaca, reaching its height as a regional capital between roughly 500 and 1000 AD. Built from massive dressed andesite and sandstone blocks, some weighing over 100 tonnes and quarried from sites many kilometers away, its surviving monumental core includes the stepped Akapana pyramid, a semi-subterranean temple, and the Kalasasaya platform, whose Gate of the Sun, carved from a single slab of andesite and decorated with a central deity figure surrounded by rows of running or kneeling attendant figures, is the site's most celebrated monument. Tiwanaku's builders fitted many stones with copper cramps set into carved channels rather than mortar, a technique that has helped some walls survive centuries of seismic activity on the altiplano. The civilization collapsed abruptly around 1000 AD, likely amid a prolonged drought, and the ruins, extensively quarried for building stone in the colonial and republican periods, were inscribed as a UNESCO World Heritage Site in 2000.