Chan Chan (chän chän) [key], ruins of an ancient city near Trujillo, N Peru. An early example of city planning, with a rectangular grid structure, it was probably begun in the period from A.D. 950 to 1400, and it is estimated that it may have contained as many as 200,000 people. Chan Chan is generally accepted as the capital of the Chimu, a pre-Inca civilization. It is on a large plain of the coastal desert, which was made arable by extensive irrigation works. Covering c.11 sq mi (28 sq km), the city comprised at least 10 self-contained, walled-in units. The walls, built of adobe brick, are decorated with relief designs.