In the coastal valleys of northern Peru, the collapse of the Wari kingdom around 1000 led to the emergence of the Chimu (850-1470). The Wari or Huari (750-1000) had
built large rectangular enclosures laid out in a strict grid patterns in their cities, such as Pikillaqta and Jincamocco. The Chimu (also called the Chimor) eventually came to control the entire northern coast of Peru from the modern border of Ecuador to Lima. Like the Moche before them, they took advantage of the extreme aridity of the land to build elaborate structures out of adobe and sun dried mud bricks. They were also extremely skilled metal workers. At the junction of the Moche and Chicama valleys, where Chan Chan was located, high quality mud and no rain made adobe a perfect building material. Unlike their contemporaries in North America, the Chimu did not confine their adobe technique to pyramids and mounds. The Chimu capital, Chan Chan, spread out across a large plain of the coastal desert, which was made arable by extensive irrigation. It covered 20 square kilometers and at its height is estimated to have had about 25,000 inhabitants.