Chan Chan was added as a UNESCOWorld Heritage Site on November 28 of 1986. The city is severely threatened by storms from El Niño, which cause heavy rains and flooding on the Peruvian coast. It is in a fertile, well-watered section of the coastal plain. The city's ruins are threatened by earthquakes and looters. Visitors to Chan Chan can enter the Tschudi Complex, a later citadel. There are other Chimú and Moche ruins in the area around Trujillo. This site was discovered by conquistadorFrancisco Pizarro.
The city has ten walled citadels which housed ceremonial rooms, burial chambers, temples, reservoirs and residences. It is triangular, surrounded by 50–60 foot walls. There are no enclosures opening north. The tallest walls shelter against south-westerly winds from the coast. North-facing walls have the greatest sun exposure, serving to block wind and absorb sunlight where fog is frequent. The numerous walls throughout the city create a labyrinth of passages.
The walls are adobe brick covered with a smooth surface into which intricate designs are carved. There are two styles of carving design: one a realistic representation of subjects such as birds, fish, and small mammals, the other a more graphic, stylized representation of the same subjects. The carvings at Chan Chan depict crabs, turtles, and nets for catching sea monsters. Chan Chan, unlike most coastal ruins in Peru, is very close to the Pacific Ocean. In 1998, The "Master Plan for Conservation and Management of the Chan Chan Archeological Complex" is drawn up by the Freedom National Culture Institute of Peru with contributions from the World Heritage Foundation - WHR, ICCROM and GCI. The plan is approved by the Peruvian Government.
To increase the farmland surrounding the city, a vast network of canals diverting water from the Moche river was created. It was only with these canals that the city's population could increase. Before the canals, the city relied on wells dug up to 15 meters deep. Many canals to the north were destroyed by a catastrophic flood c. 1100 AD, which was likely the key motivation for the Chimú to refocus their economy to one rooted in foreign resources rather than in subsistence farming. Chan Chan has water reserves called huachaques.