Grotte de Lombrives

Grotte de Lombrives is one of Europe's largest cave systems, spanning 39 km of passages across multiple levels in the Ariege Pyrenees. Excavations by Felix Regnault in the late 19th century confirmed Neolithic habitation, while Bronze Age burials and Hallstatt-period human bones were recovered in the 1980s. The Cathedral Chamber, reaching 80 m in height, could contain Notre-Dame de Paris. After the fall of Montsegur in 1244, Cathar bishop Amiel Aicard reportedly took refuge here, and the cave later sheltered Huguenots during the Wars of Religion.