High Quality Content by WIKIPEDIA articles! Natural Bridges National Monument is a U.S. National Monument located about 50 miles (80 km) north west of the Four Corners boundary of southeast Utah, in the western United States, at the junction of White Canyon and Armstrong Canyon, part of the Colorado River drainage. It features the second largest natural bridge in the world, carved from the white Permian sandstone of the Cedar Mesa Formation that gives White Canyon its name.