The Jenolan Caves are limestone caves located within the Jenolan Karst Conservation Reserve in the Central Tablelands region, west of the Blue Mountains, in New South Wales, in eastern Australia. The caves and 3,083-hectare (7,620-acre) reserve are situated approximately 175 kilometres west of Sydney, 20 kilometres east of Oberon and 30 kilometres west of Katoomba.
The caves are the most visited of several similar groups in the limestone caves of the country, and the most ancient discovered open caves in the world. They include numerous Silurian marine fossils and the calcite formations, sometimes pure white, are noted for their beauty.
The cave network is very large following the course of a subterranean section of the Jenolan River, with over 40 kilometres of multi-level passages, more than 300 entrances, and the complex is still undergoing active exploration. The caves are a popular tourist destination, with eleven show caves accessible to paying visitors and are well lit with an assortment of LED light sources.
The caves and conservation reserve are one of the eight protected areas that, in 2000, was inscribed to form part of the UNESCO World Heritage–listed Greater Blue Mountains Area. The Jenolan Karst Conservation Reserve is the most westerly of the eight protected areas within the World Heritage Site. The reserve forms part of the Great Dividing Range.
Of interest, one of the eleven general public caves, The Chifley Cave, happens to be the first cave in the world to be lit by electric light (in 1880). Two of the cave’s chambers are still decorated with historic coloured lights.