They are one of the most cavernous limestone areas in NSW, featuring rare blue stalactites, stalagmites, and 443 million-year-old Gondwana fossils formed as the ancient continent slowly sank towards the South Pole.

Cliefden Caves - under threat.

More recently, they found the skeleton of a man who died 6000 years ago, then the body of a shepherd murdered for a guinea and then thrown down a daylight hole into the darkness. The bushranger Ben Hall once hid in the same pitch-black.

But the Cliefden Caves will go under water again if a proposal for another dam across the Belubula River near Canowindra gets the nod, collateral damage in a battle between the preserved past and the preferred future.