Melin Sguthan Gaerwen · Isle of Anglesey · Wales

Melin Sguthan stands at Gaerwen, set back from the north side of a minor road leading off the A5 towards Craig Fawr and Llangefni. It is also known as Union Mill and Gaerwen Mill. The mill was one of the historic Gaerwen and Pentre Berw windmills and is situated between the village centre and the surrounding agricultural land.

The exact construction date is unclear, but the mill is late eighteenth-century and early maps and estate documents suggest that it predates nearby Melin Maengwyn. It was owned by the Plas Newydd estate and stood on the holding known as Brynsynsyn. The name Union Mill may reflect later ownership or association by Manchester interests, and local tradition links the name with a Manchester trading badge that once hung over adjoining stables.

The tower was built as a wind-powered corn mill. A late nineteenth-century photograph showed the miller Rowland Williams standing in front of the mill, with an enclosed stone platform and an external stairway giving access to an upper floor. The same photographic evidence showed a pigsty in front of the tower and a Y-wheel type chain wheel for turning the cap. These external features were later removed.

Melin Sguthan ceased working in 1913. Four years later, in 1917, it was deliberately set on fire to facilitate recovery of its metalwork for the war effort. The building survived as a dilapidated but full-height tower. An archaeological building record prepared in 2011 described it as a redundant corn mill standing to its original height, with remnants of the turning cap, blocked openings, surviving floor joists, fixtures and fittings for internal machinery, and patches of original lime render. The mill was listed at Grade II in 1968 as a surviving Anglesey windmill tower.