Garreg Ddu - Elan Valley - Welsh Water

Elan Valley

Garreg Ddu

Dam

Yours to explore

Brought to you by Welsh Water

Garreg Ddu


Height (of the submerged dam) – 20m

Length – 180m


The submerged dam can only be seen at low reservoir levels. Garreg Ddu has two purposes: to hold back water to enter the Foel Tower, and to provide access to the Claerwen valley. The Foel Tower is where drinking water is extracted to start its three day journey to Birmingham. Garreg Ddu means Black Stone.

On the bank opposite Garreg Ddu is where Cwm Elan House stood. This belonged to Mr Thomas Grove, the uncle of Percy Bysshe Shelley. Cwm Elan House, Nantgwyllt House and Dol y Mynach House were all demolished, leaving only the remains of a few garden walls.



Nearby Activities


Around Caban Bike Trail

A short (15km), moderate route that takes you around Caban Coch reservoir which should take about an hour to complete.

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Elan Valley Trail

A three hour walk from the Visitor Centre to Craig Goch following the line of the old Birmingham Corporation Railway.

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Garreg Ddu Loop

A three hour circular walk, one of Elan Valley’s most popular, takes visitors around the Garreg Ddu loop through spectacular woods and fields.

• GO TO ROUTE •

The Other Dams


Upcoming Events

19-21
Aug
Pop-Up Planetarium

The Elan Valley Dark Sky Team brings the stars to the Elan Valley Visitor Centre with their pop-up planetarium.

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1-25
Apr   Aug
Dam Open Days

Don’t miss an exclusive chance to venture into Pen y Garreg Dam…

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11-25
Aug
Archery Sessions

This is the perfect activity for the family that seeks adventure with their holidays.

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13-27
Aug
High Ropes Sessions

Platforms, bridges, unusual obstacles, a zip line and an adrenaline jump…

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4-12
Aug   Sep
Guided Kayaking Sessions

An opportunity to enjoy the beauty and tranquillity of the area from the water…

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12-13
Sep
Elan Fest 2026

An unforgettable two days of music, nature and local culture.

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1-31
Jan   Dec
Dragon Quest Trail

Elan Valley’s new Dragon Quest Trail for youngsters is roaringly good fun!

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OTHER WELSH WATER ADVENTURES

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