The Franche-Comté (Free County) was originally a part of the Burgundy, but in 1034 it became part of the Holy Roman Empire. In 1477 incorporated into France, in 1556 transferred to Spain, in 1668 occupied by the French, handed back at the subsequent peace, conquered a second time in 1674, it was finally ceded to France at the Treaty of Nijmegen, 1678. Today it is a région of France with the departments of Doubs, Jura, Haute-Saône and Territoire de Belfort.
Todays province is geographically divided into two completely different parts. The southern part is the karst area of the Jura, a series of limestone ridges in the departments Doubs and Jura. The northern part, the department Haute-Saône, is flat and covered by quarternary rsediments. All the caves are located in the Jura.