In order to restore the lake to its original size and shape, the construction of the earthen dam and its castellated stone wall were investigated. The dam wall was probably built in the mid eighteenth century and is thought to have been purely ornamental. Behind it volunteers found a number of post-medieval finds, including bits of clay pipe with the stamps of Thomas Hunt and Roger Andrus – both working in Marlborough in the late eighteenth/early nineteenth century.

At the approach to the dam from the house, close to the lake, a long stretch of wall has been uncovered, marking what appears to be the western limits of the dam wall and showing where it was joined to the Yew Walk.

West end of dam wall at the junction with a wall found at the lower end of the Yew Walk.

Crenellations on the 18c wall abutting the earthen dam.