Nant y Gro - Elan Valley - Welsh Water

Elan Valley

Nant y Gro

Dam

Yours to explore

Brought to you by Welsh Water

Nant y Gro


Height – 11m

Length – 58m


Nant y Gro was originally used to supply workers in the village with water, but was breached during testing of the charges for the bouncing bomb in 1942. The dam was one fifth of the size of the Möhne dam in the Ruhr valley, one of the targets identified by the British Air Ministry. Barnes Wallis came up with the idea of the bouncing bomb – the bouncing was not tested at Nant y Gro, but the explosives were. Have a look at the video in the exhibition hall for a clip of the tests.

Nant y Gro means Gravelly Stream.


Nearby Activities


Nant y Gro walk

Enjoy great views of Caban Coch Dam and Reservoir and marvel at the iconic beauty of Garreg Ddu Viaduct on this two hour walk to the south of the Visitor Centre.

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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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Cnwch Orange Walk

A circular trail which takes about 90 minutes to complete and includes ancient woodland and views of Caban Coch.

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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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