Chan Chan, was the largest city in pre-Columbian America. It is situated in the Moche valley, between the Pacific Ocean and the city of Trujillo. Chan Chan was designated a UNESCO World Heritage Site in 1986. Chan Chan is believed to have been constructed around 850 AD and had an estimated population of 40,000–60,000 people.
The central area of Chan Chan comprises ten extravagant walled citadels. Its walls are decorated in high relief with geometric motifs and shapes of fish and birds. The building material used was adobe brick, and the buildings were finished with mud frequently adorned with patterned relief arabesques. The centre of the city consists of several walled citadels, or quadrangles. Each of these contains pyramidal temples, cemeteries, gardens, reservoirs, and symmetrically arranged rooms. These quadrangles presumably were the living quarters, burial places, and storehouses of the aristocracy.
After the Inca conquered the Chimú around 1470 AD, Chan Chan fell into decline. In 1535 AD, Francisco Pizarro founded the Spanish city of Trujillo which pushed Chan Chan further into the shadows.