Rainbow Bridge, Utah

Rainbow Bridge is one of the largest known natural bridges in the world, spanning about 88 meters and rising roughly 88 meters above Bridge Creek near Lake Powell in southern Utah, carved from Navajo Sandstone. Unlike a rock arch, which typically forms through the erosion of a rock fin from above, a natural bridge like Rainbow Bridge is carved by a stream cutting through solid rock: over hundreds of thousands of years, the meandering creek eroded through a sandstone fin at the base of a rock outcrop, eventually breaking through to leave a graceful, symmetrical span of rock arching over the streambed. Long sacred to several Native American nations, including the Navajo, who call it Nonnezoshe, "rainbow turned to stone," the formation was designated a national monument in 1910.