Pumapunku

The stonework people argue about on the internet, and it is worth seeing in person because the argument understates it. Andesite blocks with perfectly planar faces and exact interior and exterior right angles, cut so the joints sit flush; architectural historians note those crisp interior angles would be hard for a modern mason to repeat. The famous H-blocks are blind miniature gateways, and the Tiwanaku appear to have used a set formula for shrinking monumental architecture down to models. The red sandstone came about 10 km from quarries near Lake Titicaca, the largest block around 131 tonnes, and the andesite facing stone came 90 km from the Copacabana peninsula. Radiocarbon on the deepest layer puts the start around AD 536 to 600, with three main building phases before the site seems to have been abandoned unfinished. Only about 2 of its 17 hectares have been dug. 3,850 m up, near Tiwanaku, Bolivia.