Canyon de Chelly(pronounced ‘shay’) National Monument, located in northeastern Arizona and within the boundaries of the Navajo Nation, was established on April 1, 1931 as a unit of the National Park Service. It covers 83,840 acres (131 sq mi; 339 km2) and was formed by streams with headwaters from the Chuska Mountains, and encompasses the floors and rims of three major canyons: de Chelly, del Muerto, and Monument. None of the land is federally owned. Reflecting one of the longest continuously inhabited landscapes of North America, it preserves ruins of indigenous tribes that previously lived there, such as the Ancestral Pueblo (also known as Anasazi), and the Navajo. It is one of the most visited national monuments in the United States.