The Rhaeadr y Cwm is a waterfall on the Afon Cynfal river in Gwynedd, North Wales.

[2] Rhaeadr y Cwm is located at SH736415 on the Afon Cynfal river, a watercourse that drains Migneint (to the east), an area of upland covering over 47,000 acres (19,000 ha).

[7][8] Due to the nature of heavy rainfall on the long falls over a steep drop, it has been described as "..one of the most spectacular waterfalls in Britain.

"[9] There is a proposal to build a weir above the waterfall and pipe some of the water away from a hydrolectric scheme.

[10] There are also concerns that the moisture-loving mosses and liverworts that line the gorge's sides will be affected by the water diversion.