Beneath Nottingham Castle, there is a labyrinth of man-made sandstone caves and tunnels that are strongly related to the famous legends of Robin Hood, who was said to use them to escape the Sherriff of Nottingham. <<<There's a Nottingham Castle?
*ARIZONA ~ WHITE HOUSE RUINS: stands out above lower ruins in a sandstone cave in Canyon De Chelly National Monument. These ruins were built by the Anasazi people. Anasazi is Navajo for "the ancient ones.
Derinkuyu Underground City, Cappadocia region 18 miles from Nevsehir,Turkey. It is one of over 200 underground cities discovered in the region, but it is notable for being the biggest and the deepest. With 11 floors & depth of this ancient city can a