Not every slot canyon has to be made of red and gold sandstone. Witches Gulch in Wisconsin brings some emerald colors to the party. A wood boardwalk leads hikers into the moss-covered sandstone slot, which in some places is so narrow you can touch both sides of the canyon. Located in the tourist-heavy Wisconsin Dells, visitors can get here either by car or by boat. Witches Gulch was discovered in 1871 by H.H. Bennett, a photographer credited with making the dells popular among tourists.