The Jenolan Caves are limestone caves located within the Jenolan Karst Conservation Reserve in the Central Tablelands region, west of the Blue Mountains, in Jenolan, Oberon Council, New South Wales, in eastern Australia. The caves and 3,083-hectare (7,620-acre) reserve are situated approximately 175 kilometres (109 mi) west of Sydney, 20 kilometres (12 mi) east of Oberon and 30 kilometres (19 mi) west of Katoomba. Dating back to 340million years ago, it is the oldest known and dated open cave system in the world.

The Blue Mountains are a mountainous region and a mountain range located in New South Wales, Australia. The region is considered to be part of the western outskirts of the Greater Sydney area. The region borders on Sydney's main metropolitan area, its foothills starting about 50 kilometres (31 mi) west of centre of the state capital, close to Penrith. The public's understanding of the extent of the Blue Mountains is varied, as it forms only part of an extensive mountainous area associated with the Great Dividing Range. As defined in 1970, the Blue Mountains region is bounded by the Nepean and Hawkesbury rivers in the east, the Coxs River and Lake Burragorang to the west and south, and the Wolgan and Colo rivers to the north. Geologically, it is situated in the central parts of the Sydney Basin.