Križna jama

Križna jama is kept close to its natural state, with no installed lighting and no laid-out paths: visitors are given rubber boots and a lamp and go in only with a guide. It holds 45 lakes of emerald-green water, held back by calcite dams and up to 7 m (23 ft) deep, 22 of which are crossed by boat on tours, and one of the largest deposits of cave bear skeletons in this part of Europe, with some of the bones on display in the first halls. Numbers are strictly limited because the calcite grows by at most 0.1 mm a year: only four people a day may go into the flooded part, in a single boat. With 45 animal species recorded by 2000, the cave ranks fourth in the world among cave ecosystems for biodiversity; it was first described in 1832 and its lakes explored in 1926.

Background

Cross Cave, Križna jama in Slovene and also called the Cold Cave under Cross Mountain, lies in Slovenia's Lož Valley between the karst fields of Lož and Cerknica and the Bloke Plateau, and takes its name from the Holy Cross Church in nearby Podlož. It is best known for its chain of underground lakes. Its calcite formations grow by no more than 0.1 mm a year, so only four visitors a day may enter the flooded part. With 45 species, some found only in 2000, it ranks fourth in the world among cave ecosystems for biodiversity; first recorded in 1832, its lakes were explored in 1926.

Source: Wikipedia, "Cross Cave"

What's there

• The lake chain - underground lakes held back by calcite dams and crossed by boat, past formations named the Pirate Ship, the Venetian Harbour, the Organ and the Lynx.
• The bear bones - more than 2,000 cave bear bones have been found here; some are on show in the first halls, and two skeletons put together after the 1878 dig stand in the Natural History Museum in Vienna.
• The lamp-lit visit - no fixed lighting; visitors carry the lamps they are given at the entrance, along with rubber boots.
• The unaltered passage - no laid-out paths; at Calvary the cave divides, and the boats follow the Variegated Passage to the Crystal Mountain, the largest chamber.

When to go

Year round. The underground water stays at about 8 °C, and at high water the Low Passage, where visitors lie flat in the boat, can be blocked; in January 2024 rising water after heavy rain cut off a tour group of five for two days before all were brought out unharmed. One to four hours.

Things to know

The standard guided tour lasts about an hour and keeps to the dry part of the cave, apart from a short boat trip; the four-hour tour, by reservation only, goes deep into the cave and needs full caving gear. Upstream towards the Bloke Plateau the passages end in rockfalls that are still unexplored, and downstream the water flows on through a siphon into New Cross Cave.

Nearby

In a straight line, Podlož, whose Holy Cross Church gave the cave its name, is about 1 km to the south-southwest and Bloška Polica about 2 km to the north-northeast; Lož is about 2 km and Snežnik Castle about 7 km to the south, Lake Cerknica about 6 km to the west, Cerknica about 10 km to the north-west and Rakov Škocjan about 15 km to the west-northwest.

Key facts