[1] The capital and largest town is Wonogiri, around 33 km southeast of the large Central Java metropolis of Surakarta.

The regency includes the large Gajah Mungkur Reservoir in the upper reaches of the Solo River, with a surface area of 88 km2.

[29] Most of Wonogiri Regency's area is rocky and hilly due to its location on the Sewu highlands.

Wonogiri Regency also has a dam called Gajah Mungkur Dam which has three main functions; as a power plant to produce Hydroelectricity; to provide water for rice fields around Bengawan Solo River through irrigation programs; and for tourism.

The dam has created a reservoir covering 88 km2 which lies 6 km south of Wonogiri town.