From the parking lot, it's a 10-minute walk along a jungle trail to the falls.
There is a large swimming hole at the base (to your right when you exit the woods) but there are also some small pools downriver to the left. There is a second, rougher trail you can follow that will take you up to the top of the falls, and this gives you a far better view.
This is one of the primary stops on the island day-tours that the resorts offer, so it can get pretty busy, especially on weekends. It's easy to reach though and well worth a diversion for a few hours.