Chan Chan city is located near the Pacific coast in the Peruvian region of La Libertad, approximately five kilometers west of Trujillo. It was the largest Pre-Columbian city in South America and the largest earthen architecture city in the world. Chan Chan was the capital of the Chimú civilization that stretched along the northern coast for a thousand kilometers from just south of Ecuador down to central Peru. The city itself was built about 850 CE and lasted until its conquest by the Inca Empire in 1470. At the height of the Chimú Empire, Chan Chan stretched more than 20 square km with a monumental zone of about 6 square kilometers in the center, and housed a projected 60,000 populations. Therefore, the city had 9 large rectangular citadels surrounded by thick earthen walls about 30 to 60 feet high. Moreover within these units, were thousands of buildings including temples, houses, stores are arranged around open spaces, together with reservoirs, and funeral platforms.
The walls of the buildings were every so often decorated with raised carvings representing abstract motifs and animals. Outside these nine rectangular units were four industrial sectors fixed to woodwork, weaving, and the work of gold and silver. Unluckily, the city was deprived of these valuable metals by Spanish treasure hunters who ransacked the city during the 16th century. Moreover, an area further to the south was used for farming; the land watered by an intricate system of irrigation. Chan Chan was recognized in one of the world's bleakest coastal deserts, where the average annual rainfall was less than a tenth of an inch. It was due to dry desert air that allowed the city’s earthen structure to remains to this day. Ironically, due to the changes in weather conditions, nowadays Chan Chan is endangered by too much water, as heavy rains steadily wash away this ancient city.
Source: Amusing Planet