Cave diving

international operation to rescue a group of 13 boys and 1 adult in Tham Luang Nang Non, Thailand in 2018

Deep cave in Namibia, containing perhaps the world's largest non-subglacial lake.

underwater diving in water-filled caves

recreational, technical and cave diver training organization

cave in Budapest, Hungary

cave in New Zealand

The Blauhöhle is the largest known cave system in the Swabian Alps in southern Germany. The Blauhöhle presumably originated in a time when the Danube still flowed through the Blau valley. Since the shifting of the Danube, several small rivers, the Schmiech, the Ach, and the Blau, have flowed through this valley. The cave system begins about 21 meters under water at the base of the Blautopf. It continues west and northwest, rising and falling several times until after a horizontal distance of about it comes above the level of ground water and opens into the second big air-filled chamber. The ma