Križna jama is an 8,273 m long cave system below the area of triangle between Bloke plateau, Loško polje and Cerkniško polje. The entrance into Križna jama is located 1.5 km south of Bloška Polica settlement. The cave is named after nearby Holy Cross Church in Podlož (Cerkev sv. Križa). The cave is particularly noted for its chain of subterranean lakes with emerald green water. Križna jama is the fourth-largest known cave ecosystem in the world by biodiversity. The entrance into the cave was first documented in 1832 although some engravings from 16th century are on the cave walls. The part of the cave which includes lakes and stream passages was first explored by Slovene cavers in 1926.
At Cavalry (Kalvarija; common name for the most beautiful place in the cave), the cave splits into two branches – Blatni rov (Muddy tunnel) to the north and the Pisani rov to the north-east direction. The passage through the Blata is due the slippery mud harder so most explorers choose to continue through the Pisani rov to Kristalna gora which is the largest hall of Križna jama or to Matjažev rov. Water from Križna jama continues trough the deep siphon to Nova Križna jama.
More info about the cave: Križna jama