by Mike JayThe monumental ruins of Chavin de Huantar, ten thousand feet up in the Cordillera Blanca of the Peruvian Andes, are, officially, a mystery. The vast, ruined granite and sandstone structures - cyclopean walls, huge sunken plazas and step pyramids - date from around 1000BC but, although they were refashioned and augmented for close to a thousand years, the evidence for the material culture associated with them is fragmentary at best. Chavin seems to have been neither a city nor a military structure, but a temple complex constructed for unknown ritual purposes by a culture which had vanished long before written sources appeared. Its most striking feature is that its pyramids are hollow, a labyrinth of tunnels connecting hundreds of cramped stone chambers. These might be tombs, but there are no bodies; habitations, but theyre arranged in a disorienting layout in pitch blackness; grain stores, but their arrangement is equally impractical. Instead, there are irrigation ducts honeycombed through the carved rock, elaborately channeling a nearby spring through the subterranean maze, and in the centre a megalith set in a vaulted chamber and carved with a swirling, baroque representation of a huge-eyed and jaguar-fanged entity.The archaeological consensus is that Chavin was some kind of ceremonial focus; some have tentatively located it within a lost tradition of oracles and dream incubation. But the mystery remains profound, and is considerably heightened by the bigger picture that it represents. By most reckonings, and depending on how the term is defined, civilisation emerged spontaneously in only a handful of locations around the globe: Mesopotamia, the Indus Valley, China, Mexico, perhaps the Nile. To this short list, especially if civilisation is defined in terms of monumental architecture, must now be added Peru. It was only proposed in the 1930s that Chavin is three thousand years old, and its only recently been recognised that huge ceremonial structures of plazas and pyramids were being constructed in Peru at least a thousand years earlier. The coastal site of Caral, only now being excavated, turns out to contain the oldest stone pyramid thus far discovered, predating those of Old Kingdom Egypt. So the mystery of Chavin is not an isolated one: it was the flowering of a pristine and unique culture, and one which still awaits interpretation.But theres a salient and largely unexamined feature of the Chavin culture which offers a lead into the heart of the mystery: the presence of a complex of powerful plant hallucinogens in its ritual world. The San Pedro cactus (Trichocereus/Echinopsis spp.) is explicitly featured in its iconography; like the Mexican peyote cactus, San Pedro contains mescaline, and is still widely used as a visionary intoxicant in Peru today. Objects excavated from the site also include snuff trays and bone tubes similar to those still used in the Peruvian Amazon for inhaling seeds and barks containing the powerful hallucinogen DMT. The leading Western scholar of the culture, Yale Universitys Richard Burger, whose Chavin and the Origins of Andean Civilisation (Thames & Hudson 1992) is the most authoritative survey of the territory, states plainly enough that the