Getting there:

The walk starts from the Donna Cave Section of the Mungana Caves National Park in Chillagoe. Turn left onto Frew St heading out of Chillagoe and take the first left. It's very well sign posted.

Maps

http://www.nprsr.qld.gov.au/parks/chillagoe-caves/pdf/chillagoe-map.pdf

Route/Trail notes:

Follow the trail (very well sign posted) until you reach a hole in a rock. Turn on your torches and descend into the cave. Getting into and out of the cave is the hardest part as there is a large smooth rock you need to slide down. Getting back up is less than fun but definitely achievable. The cave really only goes in one direction so you can't get lost. From the main chamber there are a few passages left and right however they lead to dead ends so it's not too difficult to find you're way back.

Retrace your steps to exit.

Note: Take spare batteries and multiple torches. This is not recommended for claustrophobics or anyone who feels uncomfortable in the dark. 

Admittedly when I was young I came here with my parents and our torch died and left the spare batteries in the car. We had to rely on our camera flash to exit. You will not be able to see your own hand in front of your face.

Permits/Costs

None.

Other References

Call or visit The Hub in Chillagoe (tourist info) for a more detailed map and trip notes. There is also Pompeli Cave just a little further on and if you take the right fork when driving in, this takes you to Donna Cave, Wullumba Art Site and Balancing Rock.