Where are these rock formations located?

Đavolja varoš (Devil's Town) is a peculiar rock formation, located in south Serbia on the Radan Mountain. It features 202 exotic formations described as earth pyramids. These formations were created by strong erosion of the soil that was scene of intense volcanic activity millions of years ago. Most of the towers have "caps" or "heads" of andesite, which protect them from further erosion.