The bluntly named “Crack in the Ground” is a volcanic fissure over two miles long and up to 70 feet deep in Lake County, central Oregon, United States. The fissure stretches diagonally from the southwest edge of the Four Craters Lava Field to the north shoreline of the prehistoric Christmas Lake. About a thousand years ago, the eruption of the Four Craters Lava and the subsequent lava flow caused the basalt rocks to crack, forming the “Crack in the Ground” or “The Crack”, as it called by the locals. With a width of just 10-15 feet at its widest, it looks like a slot canyon, even though its origin is volcanic.

Photo credit: Ron Cooper/Panoramio