Near the fabled Silk Road in China's Gansu province, these behemoths tower over the barren desert in Dunhuang Yardang National Geopark.

The park is famous for these rock formations which resemble the ruins of some ancient city.

Known as yardangs, these curious rock formations were actually created by wind erosion.

They form in environments, such as deserts, where water is very scarce and the winds are strong and unidirectional.

The abrasive materials carried by the wind erode soft, poorly consolidated rock and bedrock surfaces into elongated ridges.

The soft material gets carried away while the hard surface below remains behind.

Due to this type of wind erosion, yardangs are typically longer than they are wide.

Yardangs can also be found in the Sahara and Mojave deserts.

They have also been photographed on the surface of Mars.