Double Arch - Arches National Park

Detailed Description
This is the famous Double Arch in Arches National Park. Arches National Park has many natural arches, which formed when a layer of salt-rock formed below the red sandstone you see here. Over time, and deeply buried, the salt rose up into the sandstone, creating pockets of rock that were soft and easily eroded. Later, at the surface, the salt rock eroded away leaving behind beautiful arches or more resistant sandstone.
Sources/Usage
Public Domain.