Leat & Dam at Llanmihangel Mill

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

Llanmihangel Mill is a water-powered corn mill dating to the early 19th century. It is probably on the site of earlier mills connected with Margam Abbey, referred to in 1291, and named as Llanmihangel Mill on the Mansel Estate, in 1675. The leat has a rare form of right-angle turn into the mill gable to a concealed pitchback wheel. The first part is stone-lined. It passes under a bridge and becomes exceptionally wide for the rest of its length, having a channel some four metres broad, bounded on the south by an artificial bank, and on the north by the hillside. Near the track are remains of a former sluice and wheel-pit operated from the leat, probably the site of an earlier corn or fulling mill.

The leat runs parallel with the Afon Cynffig in a north-easterly direction. It is headed by a stone buttress upstream of the dam. The dam is a curved gravity dam of rubble and dressed stone about four metres high. The scheduled area takes in the whole earthworks of the leat (both sides of the field boundary along its bank), from the mill to the dam. The masonry dam and the masonry remains of the former mill site near the track are also included. The leat is dry and the dam has been restored.

Of national importance for the unusual morphology of both leat and dam, for their unusual completeness and group value with a fine mill building, and for the archaeological potential on this ancient mill site.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.