In the Chillagoe-Mungana National Park, dry tropical open woodlands hide underground caves of breathtaking natural beauty. Pockets of deciduous vine thicket cling to jagged limestone outcrops. Laid down 400 million years ago, the limestone has been weathered, dissolved and reformed by water to create caverns and passages of significant natural and cultural heritage value. Join a ranger on a guided cave tour to view splendid limestone formations. You can also explore some of the caves on your own. Visit Balancing Rock, an impressive tower karst (limestone pillar). Walk the nine kilometre return track to Royal Arch Bluff, looking for wallabies and birds. Drive the historic interpretive trail at the Chillagoe Smelters.