Scwd Ddwli is the collective name for two powerful waterfalls — Sgwd Ddwli Isaf (Lower Gushing Falls) and Sgwd Ddwli Uchaf (Upper Gushing Falls) — located on the Afon Nedd Fechan (Little Neath River) within the Brecon Beacons National Park in South Wales.

Both falls sit in the heart of "Waterfall Country," a stretch of wooded river valleys near the village of Pontneddfechan. The River Nedd Fechan courses over Old Red Sandstone before encountering bands of Carboniferous Limestone, shaping the dramatic cascades.

Sgwd Ddwli Isaf drops approximately 10 metres into a deep pool at its base, and is particularly forceful after heavy rainfall. Sgwd Ddwli Uchaf lies further upstream and is considered the higher of the two.

Both falls are set within dense woodland and are accessible via well-maintained footpaths. They form part of the popular Elidir Trail, which links several waterfalls along the Nedd Fechan and neighbouring Afon Pyrddin.