FamousmuseumsinEurope - Caves

The world's largest limestone mine. An endless maze of galleries with caves as large as cathedrals and narrow paths where an adult man cannot walk upright. An enormous 60 km labyrinth of passageways with caverns as large as a cathedral, and narrow tunnels where you have to walk doubled up. 2 km of the passageways are lit. A multi-media presentation shows the history of the mines. Exhibitions and films tell about bats, geology and mining. Groups are granted admission all the year round with prior reservation. Guided tours in Danish, English and German can be arranged. https://www.visitviborg.com/viborg/plan-your-trip/monsted-limestone-mines-gdk601327

The limestone of the Picardy plateau was dug out in many places to form refuges. These refugees were called "muches" (hideouts in Picard language). Those in Naours, rediscovered at the end of the last century, are the largest known: all the underground areas combined can house around 2,600 people with their livestock. The layout is remarkable: around 300 chambers, public squares, stables, wells, chimneys, and a chapel with three naves. These underground areas were used by the British forces during the First World War and were used as the headquarters of the German forces during the second world war. Exhibitions of traditional trades. In the park: games, 2 windmills from the 18th century. http://www.visit-amiens.com/tourinsoft/details/en_patrimoineculturel/PCUPIC0800010624/PCU