Greenant creek is location in litchfield, a 1.6km walk will take you to a nice waterfall and a viewing platform. You can’t get into the water there or anywhere downstream from it, as it is a sacred site for the traditional owners, however, you can swim* at a really nice rockpool right above it. I have been told it is best in wet season, these pictures are from February 2015, and it was a Saturday and we had the rockpool all to ourselves.
* it isn’t a zoned swimming site but the rangers “are aware people swim there and we don’t mind. Be careful of flash flooding as you are right above a waterfall”