The Walnut Canyon site is near Flagstaff. It is 7 miles east of I-40 and 3 miles south of exit 204. The park has a museum and a small visitor center atop a cliff. Many of the ancient dwellings were built around a U-shaped meander in the canyon, where the creek circles around three sides of a high rocky plateau, almost creating an 'island', and this region now forms the central attraction of the national monument. There are other ruins in the surround area which are not open to the public. Other dwellings of the Sinagua people can be found in the nearby Tuzigoot and Montezuma Castle monuments.

There are other ruins in the 20-by-10-mile (32 by 16 km) area, but none are publicly accessible. Many more dwellings to be seen up close in the canyon just east of the Monument, although it is illegal to enter the canyon.

Walnut Canyon was proclaimed a national monument on November 30, 1915 by President Woodrow Wilson to preserve the ancient cliff dwellings. It was transferred from the USDA Forest Service to the National Park Service on August 10, 1933.[6] As with all historic areas administered by the National Park Service, the national monument was listed on the National Register of Historic Places on October 15, 1966. (Wikipedia)

National Parks & Monuments in Distress: Wupatki National Monument

https://sites.google.com/view/nationalmonumentsindanger/nps/wupatki-national-monument