Bad Berleburg (earlier also Berlenburg) is a town in North Rhine-Westphalia, Germany, in Siegen-Wittgenstein district. It is one of Germany's biggest towns by land area. It lies about 30 km northeast of Siegen and 35 km northwest of Marburg. Bad Berleburg lies in the northeast of Siegen-Wittgenstein in the middle of the Rothaargebirge, a low mountain range. The western town limit is also the boundary with the neighbouring district of Olpe. The town is also bordered on the north by the Hochsauerland district. The town's eastern limit is likewise the boundary with the Bundesland of Hesse. The town of Bad Laasphe borders on Bad Berleburg in the south, and the community of Erndtebrück in the southwest. This is where this town of widely scattered centres is to be found, at the place where the river Odeborn empties into the Eder.