Monument Valley is a region of the Colorado Plateau in northeastern Arizona along the Utah–Arizona state line.

It's characterized by a cluster of sandstone buttes, with the largest reaching 1,000 ft (300 m) above the valley floor. The valley is considered sacred by the Navajo, the Native American people within whose reservation it lies, and in their language, it's name "Tsé Biiʼ Ndzisgaii" means "valley of the rocks".

Millions of years ago, the region was a plain covered by layers of marine sediments. Over time, tectonic forces lifted the region, and erosion from water and wind wore down the layers of sedimentary rock, leaving sandstone and clay rock formations. The harder areas resisted erosion, creating the characteristic mesas and buttes of the valley.

Monument Valley has been featured in many forms of media since the 1930s. Famed director John Ford used the location for a number of his Westerns, even so that there's a places named after him (John Ford's Point).

The elevation of the valley floor ranges from 5,000 to 6,000 feet (1,500 to 1,800 m) above sea level. The floor is largely siltstone of the Cutler Group, or sand derived from it, deposited by the meandering rivers that carved the valley. The valley's vivid red coloration comes from iron oxide exposed in the weathered siltstone. The darker, blue-gray rocks in the valley get their color from manganese oxide.