Journey to the Centre of the Earth 4,500 caves or chasms, which in this region often go by the name of 'baumes' or 'puits' are known to sports lovers, such as the Verneau caves in the Lison valley, for example are considered to form the world's longest post-siphon network (28,000 m).
Discover the underground rivers at Les Planches near Arbois. Baume-les-Messieurs, at Osselle there is a chasm which can be descended very easily. At Poudrey close to Besançon; see the miraculous chapel cave of Remonot.
Travelling “to the centre of the earth” in Franche-Comté is also a way of going back in time: these caves were inhabited by the first prehistoric men known to have lived in France.
In recent history the caves were used as refuge during invasions, hiding places for the Comtois resistants to the French invasion in the 17th Century, and partisans in the Second World War.
They are also the natural habitat of the bats which proliferate in Franche-Comté The riches hidden underground are not necessarily what you might first imagine.
