Chan Chan is the largest adobe city in the world — the sprawling capital of the Chimú empire, which controlled much of the Pacific coast of South America before the Inca arrived in the 15th century. The site covers some 20 square kilometres of desert about 5 kilometres west of Trujillo, and even in its current eroded state gives a vivid impression of the scale of Chimú civilization.
The nine royal ciudadelas (palace complexes) each follow the same basic layout: high walls enclosing ceremonial courts, storerooms, an audiencia, and a burial mound. The Tschudi Complex is the best restored and the main visitor circuit. Its interior walls are decorated with friezes of fish, pelicans, and geometric patterns in bas-relief — extraordinarily intact given that they're made of unfired mud.
The site is best visited in the morning, before the midday heat sets in. Taxis from Trujillo centre cost a few soles, or you can take a minibus headed toward Huanchaco.