Cross Cave (Slovene: Križna jama), also named Cold Cave under Cross Mountain (Mrzla jama pod Križno goro), is a cave located in the Lož Valley, Slovenia. The cave is named after nearby Holy Cross Church in Podlož. The cave is particularly noted for its chain of over 45 subterranean lakes of emerald green water. With 45 species of organisms, some not discovered until 2000, Cross Cave is the fourth-largest cave ecosystem in the world by biodiversity. The cave was first documented in 1832, but the part of the cave which includes lakes and stream passages was first explored by Slovene cavers in 1926. Over two thousand bones of the cave bear have been found in the...