Walled sinkholes represent one of the main features of the wooded eastern slopes of the Gradac-Perun ridge. Sinkholes filled with a large amount of quality soil are arranged in a relatively regular pattern along several levelled shelves. People used to grow hardy cereals and vegetable crops in them such as rye, barley, potatoes and cabbage. In order to protect the crops and plantations from the livestock that grazed freely on the surrounding pasture, the sinkholes were fenced off with dry stone walls. The abandonment of the pastures resulted in forest overgrowing the area, including the sinkholes.
