Chan Chan Archaeological Zone

The adobe brick city of Chan Chan on Peru's north coast was the capital of the Chimu Empire from 900 to 1470 AD and at its peak housed 60,000 people in a complex of nine royal compounds covering 20 square kilometres -- the largest pre-Columbian city in South America and the largest adobe city in the world. UNESCO inscribed it as a World Heritage Site in 1986 and immediately placed it on the Endangered list due to erosion damage from El Nino flooding, making urgent preservation one of archaeology's most pressing challenges.