Pivka Jama, Show cave in Postojna, Slovenia

Pivka Jama is a cave system near Postojna carved by an underground river that flows through limestone passages. The cavern descends to a depth of roughly 65 meters and is accessed by stairs that lead visitors deeper into the formations.

Pivka Jama was first explored in 1850 by Adolf Schmidl and later investigated by Édouard Alfred Martel in 1893. After World War I, Italian military forces tunneled through limestone to connect the cave system with nearby Črna Jama.

The name Pivka Jama comes from the Pivka River, which enters the cave system in Postojna Cave and resurfaces at Planina, more than two kilometres away. Guided tours follow a route upstream past large halls and along a path cut into the rock face in 1925. Adolf Schmidl, who explored the cave in 1850 and 1852, wrote that if any cave in Carniola deserved to be made accessible, it was this one.

Access to the cave requires descending a long flight of stairs, which demands moderate physical fitness. Sturdy shoes with good grip are essential since the steps can be damp and slippery from underground moisture.

The 100-metre artificial tunnel linking Pivka Jama with Črna Jama is normally closed by a gate; behind it, a second short passage leads into the Postojna Cave system. Cave divers have explored about 950 metres of the flooded connection between the two caves, while a further 1,500 metres remained unknown as of 2007.