Offa's Pool Dam

Cadw's description

Location

Located approximately 1.7km SE of Leighton church and situated in a woodland plantation on the W side of a private forest road (also Offa's Dyke long distance footpath). The pool is fed by 2 streams.

History

Built with an earthen dam in the late 1850s and subsequently replaced by a brick dam. Offa's Pool is the uppermost of a series of ponds feeding Leighton Farm and Leighton Hall. It was specifically intended to supply water to drive turbines at Leighton Farm. The pool was part of the Leighton Estate, acquired by the Liverpool banker John Naylor in 1846-47. Naylor embarked on an ambitious programme of building, notably Leighton Hall, church and Leighton Farm, all designed by W.H. Gee and completed by the mid 1850s. Naylor introduced new rational farming methods at Leighton, notably pioneering the recycling of manure as fertiliser and the use of turbines and funicular railways. Naylor continued to extend and improve the Estate until his death in 1889. His grandson, Captain J.M. Naylor, sold Leighton Hall and the Estate in 1931.

Exterior

Brick dam wall approximately 70m long which returns at either end into a natural bank. The inner face has shallow buttresses and the wall has a stone coping. On the exterior side of the wall is an earthen ramp. Mid way along the inner face is a cast iron sluice box.

Reason for designation

The Leighton Estate is an exceptional example of high-Victorian estate development. It is remarkable for the scale and ambition of its conception and planning, the consistency of its design, the extent of its survival, and is the most complete example of its type in Wales. Offa’s pool and its dam are an important element of this whole ensemble at Leighton. The dam demonstrates the scale of civil engineering undertaken at Leighton in the C19, and is specifically associated with the application of new technology on the Estate.