You may expect sand when you think about a desert, but the Devil’s Golf Course in the Mojave Desert within Death Valley National Park, considered the hottest place on earth and the driest place in North America, has a floor of strange, solid shapes. It is a salt pan, a huge, dried-up lakebed that stretches about 40 miles.

The salt pan was the site of Lake Manly, which reached depths of 600 feet, according to Amusing Planet. As climates changed, the lake dried up and filled again, but only to about 30 feet.

(MORE: Abandoned Theater in the Sinai Desert)

Between 2,000 to 4,000 years ago, a lake dried up leaving behind minerals on the lakebed. Over the years, the lakebed was sculpted by the elements into its now characteristic pinnacle shapes.

According to the U.S. Geological Survey, the pinnacles form as salty water evaporates from the mud underneath, and salty residue is left behind. Visitors can hear tiny pops as the salt crystals expand and burst in the heat. But they grow as slowly as an inch every 35 years. Weather continues to erode the salty ground into intricate shapes.