The tallest waterfalls in Wales

Which bit is supposed to be measured?

For details of routes to these waterfalls, see the waterfall walks page.

This is not an official list (though it is substantially better than any other lists I have encountered). I do not expect this list to be complete, since I may have missed important waterfalls in Mid and North Wales. Add to that the fact that most waterfalls have no information available at all, and it becomes quite hard to produce this list. In many cases, careful reading of high scale maps is the only option. If you can offer any details, please get in touch.

Tallest single drop

This lists waterfalls with a single drop of 20 metres or more, and gives the heights of the drops that are tall enough.

To qualify for the list of single drops, a waterfall must fall continuously from top to bottom. While it is allowed to make contact with the bedrock, in cases such as a horsetail fall, cascade, or a nearly-vertical plunge, it must not have any sections that are that are gentle enough to be classed as a stream, river or plunge pool separating parts of that fall into separate distinct falls. It is not always easy obtaining this information for waterfalls, as people sometimes only give total height (or in some cases, nothing at all), in an attempt to make the waterfall seem as tall as possible. This is definitely the case for Pistyll Rhaeadr, for example, for which the only reliable information is the total height, when the waterfall is in three very distinct sections.

Waterfall single drops of 20 metres or more
WaterfallHeight (metres)CommentsImage
Devil's Appendix93May be broken by low flow or high winds.View image
Pistyll y Llyn91View image
Maesglase Waterfall Middle Fall85View image
Afon Hengwm75View image
Pistyll Gwyn, Afon Pumryd72View image
Diffwys Dwr/Craig y Rhaeadr61View image
Nant y Cafn Falls Lower Cascade45View image
Rhaeadr Y Carreg Wen45Calculated. Sometimes misquoted as 21 metres.View image
Pistyll Rhaeadr40Estimated. Often mistakenly claimed to be the tallest in Wales.View image
Nant y Cafn Falls Upper Cascade40View image
Ffrwd Fawr40View image
Ffrwd Ferin/Rhaeadr Myherin40Calculated. Height often grossly exaggerated.View image
Nant Bwa-drain39Branch only appears in higher flow.View image
Aber Falls37Sometimes mistakenly quoted as 79 metres.View image
Nant Cwm-du Falls36View image
Maesglase Waterfall Lower Fall34View image
Rhaeadr y Bedd outflow cascade34Water artificially diverted to the head of this natural cascade.View image
Ffred Ferin Isaf/Rhaeadr Myherin Isaf30Estimated.View image
Pistyll Blaen-y-cwm30View image
Ffrwd Milwyn28View image
Sgwd Henrhyd27View image
Sgwd Einion Gam26View image
Nant y Gwaith Lower Fall26View image
Melincourt Falls25View image
Mynach Falls25Estimated.View image
Pistyll Gwyn, Afon Las25Estimated.View image
Nant y Cafn Falls Spout24View image
Rhaeadr y Bedd original cascade22View image
Nant Bwa-drain22Normal and high flow.View image
Cwm Rhaeadr Waterfall22View image
Pen Pych/Berw Wion21View image
Rhaeadr Dyserth21View image
Pistyll Cain20Sometimes quoted as 46 metres in total, by including remote cascades.View image
Devil's Kitchen20Estimated.View image
Rhaeadr y Cwm20Estimated. Height is often exaggerated to as much as 37 metres.View image
Nant y Gwaith Upper Fall20View image
Nant y Gwaith Middle Fall20View image
Ceunant Mawr/Llanberis Falls20Height artificially reduced to 18 metres by damming the plunge pool.View image

Tallest total height

This lists waterfalls with a total height of 40 metres or more (chosen because there are too many waterfalls requiring etimates below that height), and gives their heights.

To qualify for the list of total heights, the sections of the waterfall must fall without significant sections of stream or river between drops. Plunge pools and intermediate cascades are allowed. It can be difficult to decide where to draw the line. Small streams that tumble down mountain scarps in a series of repeated, broken cascades are intentionally discounted, not because they do not deserve recognition, but because there are simply too many of them to discover, and it is too difficult to obtain accurate information for them. If you are looking for these, the tallest I know are the streams in Cwm Idwal, with a few being about 200 metres tall, and one to the southeast of the Devil's Kitchen having 300 metres of height dropped in a series of cascades. There are also some small streams that drop very steeply for over 600 metres down the southwest slopes of Glyder Fawr. Examples in Mid Wales would include Rhaeadr Du and Rhaeadr Wen at Tarren Bwlch Gwyn near Aberhosan, both about 250 metres high, but never breaking into proper waterfalls.

Waterfall total heights of 40 metres or more
WaterfallHeight (metres)CommentsImage
Maesglase Waterfall160Continues for another 60 metres as a cascading stream.View image
Pistyll y Llyn160View image
Pistyll Gwyn, Afon Pumryd152View image
Nant y Cafn Falls130View image
Afon Hengwm110View image
Pistyll Blaen-y-cwm107View image
Aber Falls100Sometimes quoted as 91 metres due to conversion errors.View image
Pistyll Rhyd-y-meinciau/Rhiwargor Falls/100View image
Nant y Gwaith Falls100View image
Devil's Appendix93View image
Mynach Falls90View image
Rhaeadr Bach upper section90Estimated.View image
Rhaeadr y Cwm80Calculated.View image
Nant Gwynllyn Falls80View image
Cwm Rhaeadr Waterfall80View image
Llaethnant main section76View image
Pistyll Rhaeadr73Often mistakenly claimed to be the tallest in Wales.View image
Ffrwd Ferin/Rhaeadr Myherin70Height often grossly exaggerated.View image
Rhaeadr Y Carreg Wen upper section70View image
Dol-goch Tributary Waterfalls65View image
Diffwys Dwr/Craig y Rhaeadr61View image
Rhaeadr Porth-llwyd61
Nant Cwm-du Falls60View image
Arthog Waterfalls60View image
Mossy Seat Falls60View image
Rhaeadr Y Carreg Wen lower section60View image
Cwm Cerrig-duon60Unconfirmed
Nant Bwa-drain52Calculated.View image
Rhuddnant Gorge Falls50View image
Rhaeadr Bach lower section50Estimated.View image
Dulas Gorge Falls50View image
Nant Ddeiliog Falls50Unconfirmed
Rhaeadr Rhosan45View image
Nant y Cae Falls45View image
Ffrwd Fawr40View image
Rhaeadr Ogwen40Estimated.View image
Nant y Sarn Falls40Estimated.View image
Ffrwd Milwyn40View image
Llaethnant upper section40View image

It may be interesting to note that Berw Nant yr Ychen is probably the tallest waterfall in South Wales in terms of total height, at nearly 30 metres. Sgwd Henrhyd, on the other hand, has only a single drop, and is only a few metres shorter.