Lamprechtsofen

Lamprechtsofen (also called Lamprechtshöhle, Lamprechtsofenhöhle or, together with a connected cave, Lamprechtsofen-Vogelschacht) is a limestone karst river cave in Austria. With a depth of 1735 m, it is one of the deepest caves in the world. Before the discovery of the Krubera Cave in Georgia, it was the deepest-known cave in the world. Lamprechtsofen is located 2 km northwest of Weißbach bei Lofer (Salzburg), Austria, in the Leogang Mountains.

Early history
The cave has been known for centuries. In 1701 it was walled up to prevent the intrusion of treasure seekers, who were lured to the cave by legends of wealth hidden by a knight named Lamprecht after the Crusades.

In 1905, several human skeletons were found in the cave, probably the remains of treasure hunters. At the same time, a 600 m portion of the cave was opened to the public as a show cave.

Exploration and depth record
The exploration of Lamprechtsofen has been primarily conducted from the bottom (from the resurgence of its cave river), rather than the top-down exploration typical for vertical caves.

On August 19, 1998, a team led by Polish caver Andrzej Ciszewski discovered a connection between Lamprechtsofen and the PL-2 cave system, which established the height difference of the united cave system as 1632 m. This new discovery made Lamprechtsofen the deepest-known cave in the world for less than three years, as Krubera was discovered in June 2001 to be 2197 m deep.

As of 2014, Lamprechtsofen is the fourth-deepest cave in the world, as two more Georgian caves have since been discovered to be deeper. Sarma Cave is 1830 m and Illyuzia-Mezhonnogo-Snezhnaya Cave is 1753 m. On August 14, 2018 a Polish expedition connects the CL3 chasm to the Lamprechtsofen allowing the cavity to reach the depth of 1735 m.

Show cave
Today, about 700 m are open to visitors, a portion of the cave that covers a 70 m altitude difference.

Because of the cave's river, it is subject to flooding from heavy rain and melting snow. As such, visitors and explorers have been occasionally trapped in the cave.