At a stately 340 million years, the Jenolan Cave network is the oldest open cave system in the world and are absolutely spectacular. Located in the beautiful Blue Mountains World Heritage Area the Jenolan Caves are only a couple of hours drive from Sydney and make a great day or overnight excursion. The vast cave network has over 40 km (25 Miles) of multi-level passages offering easy site seeing walks, educational and historical tours to active adventure caving.