Rock Paintings of the Sierra de San Francisco

For some 1,400 years — from roughly 100 BC to AD 1300 — a now-vanished people painted the canyon walls of Baja California's Sierra de San Francisco with human figures and animals in astonishing scale and colour. Desert dryness and sheer remoteness kept the murals crisp, leaving one of the world's great concentrations of rock art inside the El Vizcaino reserve. UNESCO recognised the paintings as World Heritage in 1993.