Three Mittens, Monument Valley Navajo Park
UT , USA
Monument Valley is not really a valley, but an upwarp of sedimentary rock that is at least 260 million years old, surrounded by sentinels that have yet to fully erode. The floor itself is more than a mile high, part of the 130,000 square-mile Colorado Plateau. Sandstone is easily eroded, and the wind, rain, cycles of frost and heat have been at work, cracking and chiseling the valley to its present form.