Perched at an altitude of 3 850m on a bare plateau 15km south of Lake Titicaca, the city of Tiahuanaco, a UNESCO World Heritage Site, has retained its air of mystery. Its golden age was between the 7C and 9C AD, but it was the capital of a culture that extended from 1600 BC to 1200 AD and spread to Ayacucho and Nazca. Only the ceremonial centre has stood the test of time; the museum artefacts, monumental carved stones and semi-subterranean temple are impressive.