DONNA CAVE – CHILLAGOE
The Donna Cave is one of three National Parks Tour Caves in Chillagoe, Queensland, 200 Kms west of Cairns. The Donna, Trezkinn, Pompeii and Bauhinia caves can be accessed from the Donna Cave car park, 1.8 km from Chillagoe. None of these caves are wheelchair friendly.
The Donna Cave is accessible only during National Parks guided tours and takes its name from a formation just inside the entrance that depicts Madonna and child. The entrance is a steep descent of steps into a huge picturesque chamber adorned with a variety of decorations. Graffiti dating back a hundred years is evident but not often a feature pointed out by the guide. The infrastructure is well done with stainless steel handrails, platforms and tastefully positioned lighting.
Geology 
It’s generally believed that the landscape around Chillagoe began to form about 400 million years ago when limestone was deposited from the remains of huge coral reefs on the bed of a shallow sea. After subsequent tilting, folding and erosion combined with volcanic action, the subterranean landscape eventually became exposed as Australia eroded away to form the weathered limestone and marble that today towers over the surrounding plains. As these limestone bluffs were being exposed, fluctuating groundwater levels slowly dissolved some of the limestone, creating caverns and passages. Acidic rainwater began to dissolve the porous limestone as it seeped through and into these caverns where it evaporated to create decorations or secondary formations such as stalactites, stalagmites and flowstones. These caves would have been first exposed as sinkholes, trapping land based animals of the time. Fossilized bones of many animals including those of the extinct giant kangaroo, giant wombat and crocodile have been found in some of the caves.
More information can be found at http://www.nprsr.qld.gov.au/parks/chillagoe-caves/about.html
or have a look at the Perentie Tours home page