This waterfall is located within the popular Elidir Trail on the outskirts of Bannau Brycheiniog (Brecon Beacons National Park). What makes it secret is that it's not a part of the official trail and can be slightly awkward to get to. When you reach Sgwd Gwladys on the well marked trail, you'll need to carry on off trail and up river for another 15 mins or so.