Time Out says
Geology doesn't get more showstopping than this
To the untrained eye, these caves are pretty spectacular, but to a geology nerd, they’re downright mind-blowing. Stalactites, stalagmites, flowstones, cave coral, helictites, stone shawls and subterranean lakes – it’s geological bingo down here, including some incredibly rare rock formations that are seldom seen by the general public. Most of the individual caves of this system can be accessed individually, but make sure Junction, Fig Tree and Wollondilly are part of your visit, as well as the Dennings Labyrinth, so long as you’re feeling adventurous and don’t mind a little claustrophobia. The Wombeyan Karst Conservation Reserve also has holiday cottages, campgrounds, and guided tours of both the caves and surrounding bushland, so this is an ideal destination for an outdoorsy weekender during the warmer months.