RUINS on Peru’s desert coast dated to some 4,700 years ago suggest an earlier focus of civilisation than any so far identified in the New World. The site of Caral, in the Supe Valley north of Lima, covers 66 hectares (165 acres) and includes pyramids 21m (70ft) high arranged around a large plaza. “What really sets Caral apart is its age,” Roger Atwood reports in Archaeology. “Carbon dating has revealed that its pyramids are contemporary with those of Egypt and the ziggurats of Mesopotamia.” These are among the earliest monumental architecture in the Old World. Surveys and excavations in neighbouring valleys, Atwood says, suggest that Caral “stood at the centre of the first society in the Americas to build cities and engage in trade on a large scale”. Caral has been investigated over the past decade by a Peruvian team headed by Dr Ruth Shady. Other sites in Peru are as early, but the report notes that “none approach the size and scope of its architecture. Whether it can truly be seen as a civilisation comparable in attainment with contemporary Egypt and Mesopotamia is doubtful, but it demonstrates that the tradition culminating in the Inca Empire had deeper roots than anyone imagined.