>Dol-y-Mynach Dam the first of the Claerwen Valley Dams.
Also known as the unfinshed dam. Dol-y-Mynach, which was to be 101 ft (31 metres) high and 938 ft (286 metres) long was never finished. This was to be the first of three dams (Dol-y-mynach, Ciloerwynt and Pant-y-beddau) to be built in the Claerwen Valley but due to both world wars the three dams were never built. Claerwen dam was built instead. There is a small tower just upstream of Dol-y-Mynach dam which marks the entrance of the Dol-y-Mynach Tunnel. This feeds water from the Claerwen directly into the Garreg Ddu reservoir during droughts. The Tunnel is just over 1 mile long.
Height - 10.7 meters
Total capacity - 150 million gallons