A circuitous leat eventually feeding a mill, but possibly involved in water supply and garden features along its route.
The leat springs from the Rhiangoll and runs roughly 772m south-westward. It passes through a pool north-west of the castle (at SO18432130), then runs south and south-east about the castle motte moat, to a pond & mill (NPRN 309429) immediately south of Tretower Court. The mill may be one of those recorded in 1305 (Ralegh Radford 1960 (Brycheiniog 6, 12).
At least two channels, possibly ornamental/garden features, appear to spring from the leat, possibly to feed a pool to the south (NPRN 309428). A further branch, leading east-north-eastward from south of the castle & preserved by current boundaries, may have supplied the court.

Associated with:

Tretower Court (NPRN 16305)
Tretower Castle (NPRN 306010)
Park/gardens (NPRN 86119).

RCAHMW AP965103/47-50

J.Wiles 11.11.03