Canyon De Chelly National Monument, like many other amazing works of natural beauty, is located in Arizona. According to this monuments website, one of the reasons it is a national monument (authorized as such on April 1, 1931) is because of the rich history it possesses.

The land belongs to the Navajo Indians and possesses ruins of Indian villages built between AD 350 and 1300! Look at the picture taken from Terragalleria, of this cliff. If you’ll notice at the bottom there is a small village tucked in the bottom of the cliffs wall.
This Youtube video contains some interesting info about drawing found on the canyon’s walls:

10 seconds of the carved out village ruins

Some good panaramic views:

Here are a few more interesting photographs of the area:
Spider Rock
White House Anasazi
Pink Sand Dunes
The monument consists of 83,840 acres of land. Here is the satellite view from Google Maps.