September 01, 2007
The photo above shows possibly the world's largest natural bridge, namely Rainbow Bridge. It's located near Lake Powell, Utah, in Rainbow Bridge National Monument. The base of Rainbow Bridge is composed of Kayenta Sandstone, which was laid down by inland seas and shifting winds over 200 million years ago. The bridge itself is composed of Navajo Sandstone. Rainbow Bridge spans 275 feet (84 m) across Aztec Creek. At the top of the arch the sandstone is 42 feet thick and 33 feet wide (13 m x 10 m). Photo taken on September 27, 2006.