Veliki Krs is a large mountainous area that rises to a height of 1148 m and is located about ten miles northwest of Bor, west of road Bor - Gornjane. It is long 9km and 3 km wide. From the east, south and west it is surrounded by Timok eruptive area. It is made of reef limestone of Cretaceous age. The site has more forest areas, but there are hardly accessible locations pristine pure nature.Mali Krs builds on from the Veliki Krs. The highest peak is Gavran (Raven) – 929 m. It is 6 km long, and up to 2 km wide. It represents a part of the watershed between the rivers Pek and Porec. It is built of limestone and well forested.