Increasing access to Elan Valley’s archaeological and built heritage

Elan Valley is 72 square miles and the opportunities to explore are endless.  However, much of the diverse heritage is not currently visible or accessible to visitors.  The project will enable safe public access to six heritage sites, including:

Half-built Dol y Mynach Dam

This dam was never completed by the Victorians. It was built in the first phase and planned to be completed in a second phase of work.  However, the World Wars put a stop to its completion.  After World War 2, technology had developed and called for just one larger dam upstream (Claerwen). 

Dol y Mynach Dam has an important role, it holds back a small reservoir which is linked to a tunnel (Dol y Mynach tunnel), this flows into Garreg Ddu reservoir and then down the aqueduct to Birmingham.

Shielded by vegetation from the roadside and with no signage or interpretation, visitors are missing out on an important section of Elan’s heritage. An access track to Dol y Mynach Dam, signage and quality interpretation will give visitors a different experience.  The access track will also link with the Bird Hide on the shore of Dol y Mynach reservoir. The shallow reservoir is wonderful for wildlife and is a Site of Special Scientific Interest and like the dam itself, many visitors are unaware there is a bird hide here.

Dambusters site at Nant y Gro

During the building of the Elan Valley dams, a small coffer dam was built at Nant y Gro.  This provided electricity and water to the workers.  In the Second World War, the dam had another important role.  It was determined that the Nant y Gro dam had the same design as the Ruhr Dams in Germany, identified as an enemy target.  Barnes Wallis used Nant y Gro to help create his bombs for the successful ‘Dambusters’ attack.  The remoteness of the dam was an advantage for the top secret trials to be conducted without fear of being observed.

There is a common misconception that the reservoirs were used to practice the actual bouncing of the bomb. However, this was not the case.  Instead, Barnes Wallis tested the explosives here.  The first attempt only blew the top off the dam.  This led to the realisation of the need to sink the bomb.  A mine was suspended at the optimum depth from scaffolding halfway along the 180ft dam and detonated remotely. The success of this trial confirmed that it would be necessary to deliver an explosive device underwater and in direct contact with the wall in order to destroy the dam. His second attempt, in July 1942, saw him sink the explosives and breach the dam.  He used these calculations to build the bouncing bomb used in the successful attack in 1943.

Our project will remove vegetation from the dam remains, and improve signage to the site.  We will also update the interpretation boards at the site and on the accessible trail opposite the valley to tell the story of the dam.

World War II Pillboxes

During 1940-1941, pillboxes were built to guard Birmingham’s water supply.  These specifically covered the Foel Tower and Garreg Ddu dam.  Four pillboxes were constructed, three of which remain today and are scheduled ancient monuments.  Soldiers would be stationed at the pillboxes and would aim their machine guns, from a protected vantage, in readiness for an attack.

The remaining Pill Boxes sit on the Foel hill overlooking Garreg Ddu reservoir, with two sited near the Foel Car Park. This project will improve sight lines between the pill boxes and install interpretation boards, providing details of the sites.

Medieval rabbit farming complex

From the Heritage at Risk survey, Esgair-y-Ty was highlighted as a national significant asset. This impressive group of pillow mounds are about 40 metres long, 6 metres wide and a metre high and demonstrate an early example of rabbit farming and intensive agriculture in Elan.

Improving access and navigation to these areas will help people picture the rabbit farming complex and a different way of life at that time.

We will use augmented reality to demonstrate the boundaries of the pillow mounds, providing digital interpretation for the site.

Roman Marching Camp

Found on Esgair Perfedd, on Cwmdauddwr Common, this example of a temporary Roman fort or 'marching camp' is visible by a low earthwork enclosure. 

The camp encloses an area of just over 6 hectares and was built to house a force of about 4,000 men and their supplies in tented accommodation for perhaps only a matter of days. The fort is likely to belong to the period between about AD 74–80.

The Camp was only discovered in the 60s as the boundary is only visible from an aerial position.  Therefore more visitors are unaware they’re travelling past what was a Roman Camp. 

Our project aims to use augmented reality to bring the area to life.

Cwm Elan Mine

Worked between 1796 and 1877, Cwm Elan Mine is tucked in the Nant Methan Valley in the hills above a popular walk alongside Garreg Ddu reservoir.

Within this project, we will install signage to the mine where possible and identify the route on the website and in publications.

Download the project plan.