Delicate Arch, Arches National Park, Utah

© Mark Brodkin Photography/Getty Image

Delicate but enduring. Arches National Park, Utah

This stunning structure is Delicate Arch, the most famous of 2,000 stone arches scattered around Arches National Park in Utah. It is made up of Entrada Sandstone, the grains of which once formed a massive desert. They were cemented together by minerals, forming sandstone riddled with tiny holes. Over millennia, the rain seeped in and slowly dissolved the rock from the inside, forming these eye-catching sculptures. Most of the arches in the national park are formed from Entrada Sandstone and were once buried by other rock layers. They won't last forever, but over time, new shapes will emerge from the layers of rock below to replace them. Every year, close to 1.4 million people visit the park to see Delicate Arch and this slowly shifting landscape for themselves.