Image source: http://img11.deviantart.net/7493/i/2013/057/3/6/antelope_canyon__psychedelic_by_alierturk-d5w9l15.jpg
Antelope Canyon, Arizona, USA
Made by: Water
Flash floods formed the smooth walls of the slope canyon by erosion. Fissures in the Navajo Sandstone allowed moisture to get in and to shape the steep canyons by high speed. The floods picked up sand, causing the same effect as sandpaper.