The first signal station in County Galway is located on Inisheer, the second largest of the Arran Islands. The signal station communicated with the station at Hags Head in County Clare, to the south east and with the station on Inishmore to the north west.
The signal station on Inisheer is located at 65m OD on the crest of the large flat topped hill that dominates the island and has expansive views in every direction except the south west. The site is approached via a steep lane that leads up from the harbour area, passing by the important cashel and hall house complex known as Dún Forma and Caisleán Uí Bhriain respectively. The site is considered to be unsafe for visitors and a sign on the gate states that entry is not permitted. Fortunately the site can be easily observed from the adjacent road and given the sites good level of preservation it is well worth a visit.
The signal station consists of a well preserved signal tower set within a large rectangular enclosure with an almost complete mortared stone wall that measures around 50m by 30m. The current entrance is through a gate at the northern corner of the enclosure and, all though this is presumed to be a secondary alteration and the location of the original entrance is not clear. There are two later buildings located within the enclosure, a mid 19th century school house, and a small toilet block constructed against the south western wall of the enclosure. A large water tanks has been built at the east corner of the enclosure, and the enclosure wall has been removed in this area, although most of the tank lies outside of the signal station.
The tower is located on the long axis of the enclosure towards its north eastern end, around 10m south west of the enclosing wall. The signal tower is largely complete to the full height of its walls and measures 5.85m across. The signal tower features the usual arrangement of a first floor doorway protected by a machicolation and two small bartizans on the corners of the wall opposite the doorway. The exterior of the tower is covered in a heavy layer of render in which the impressions of weatherproof tiles can be seen. In a few areas around the top of the tower patches of intact slate can be seen.
The tower follows the standard arrangement of internal features, with a semi basement, four ground floor windows, a ground floor fireplace set between two alcoves, a split mezzanine level between the ground floor and first floor, four first floor windows, a first floor fireplace set between two alcoves, a small attic, and it would have featured an accessible roof area with entrances to the corner bartizans and the machicolation over the doorway. A drainage channel runs down the western corner of the north eastern wall, that brought rain water from the roof down into the semi basement.
The dressed stone that would have surrounded the windows and capped the walls have mostly been removed. One of the ground floor windows on the north west wall has been expanded up to provide ground level access to the interior, whilst a large hole has been knocked through the north east wall, removing large parts of the ground floor fireplace.
In the centre of the enclosure is a substantial mid to late 19th century schoolhouse. This building is set around 13m south west of the signal tower and is arranged with its long axis at right angles to the long axis of the enclosure. The school house measures roughly 19m by 8m and is divided into two equally sized rooms. Fireplaces are located on the dividing wall, which is topped by a tall brick built chimney. The front north eastern wall features a wide porch, itself split into two separate entrances, each serving one of the classrooms. The rear south western wall shows the scar of a now demolished wall that ran from the midpoint of the school house towards the toilet block on the south west wall of the enclosure. The outbuilding is rectangular and measures 4.8m by 3.12m with a doorway on the north west wall and a now blocked doorway on the south east wall. The roof of this building sloped downwards into the enclosure. The division of the school, yard and toilet into two halves, each with its own entrance is likely the result of the separate schooling of girls and boys within the same building.