Seven Keyholes Slot Canyon in Nevada

Slot canyons usually have nearly parallel sides, or even taper downward. They are common in the Aztec/Navajo sandstone, which is responsible for so much spectacular scenery in this part of the world. This slot canyon is unusual, however, in that it's wider at the base, with a nearly circular cross-section.

The overall canyon cross-section looks something like an old-fashioned keyhole turned upside down. Presumably, the sandstone near the bottom of the canyon is a bit softer so it's eroded out more. There are several different keyhole-shaped sections of the canyon, separated by breaks nearly perpendicular to the canyon, but even so "seven" keyholes is a bit of poetic license.

More weird erosional forms occur in the immediate vicinity of the slot canyon entrance. They are reminiscent of the erosional features seen in Little Finland, which is not far away.