Mermaids Fall is located in a large grotto called Mermaids Cave that is accessed either from downstream on the walking track or, down a great set of old stone steps down through a crack in the rock.
These falls flow best after good rain, othertimes they are barely a trickle, the day I was there, they were just a tad better than a trickle. Easy to get to and a good one for kids to visit.
If you are a Mad Max fan, this location and waterfall was set dressed to look like it was underground and was the home of the lost tribe that found Max in Mad Max 3.