Rathlee Signal Tower is located within the dispersed settlement at Rathlee. The area is part of an expansive coastal plain and the site has expansive views in all directions. The nearby tower at Lenadoon Point is too low to be seen from ground level at the site, whilst the signal station to the east, Carrowmably, is now obscured by trees. The site is accessed from the road that runs through the settlement. The site consists of a well preserved signal tower that survives to its full height but no enclosure is present.
The signal tower measures 5.8m across and is orientated with its first floor doorway facing north towards the ocean, with four windows on the the east side and the west side and the bowed wall containing the chimney to the south. A shallow machicolation protects the doorway and the southern corners are protected by small rounded bartizans. Dressed stones are present around the first floor windows and first floor doorway. There are no dressed coping stones at the top of the walls. A fine chimney stack is present on top of the southern wall. The exterior of the tower is covered in a layer of render but it lacks the impressions of slates seen at the sites on Inisheer and Inishmore on the Aran Islands in County Galway.
In the centre of the southern wall there is a grey stone sign that reads “Rathlee Signalling Tower. In memory of those who worked here and all who perished at sea. 2nd July 2006.” To the right of this is an older white sign that reads “Ruin of O’Dowd castle Lochtar Rath a seat of Kings of Tirerach” apparently mistaking the site for Rosslee Castle some 5km to the west.
To the right of the white sign a square hole penetrates into the wall. The hole contains a solidly anchored horizontal metal bar, behind which is a heavy metal sphere that appears to be a small cannon ball.
The interior of the tower features all of the typical arrangements, with a largely infilled semi-basement, four ground floor windows, a ground floor fireplace flanked by alcoves, slots for a split mezzanine level between the ground floor and first floor, four first floor windows, and a first floor fireplace flanked by two alcoves. There is no evidence of an attic between the first floor and the roof. Interestingly the slots that held the mezzanine floors on the north and south wall slope downwards into the centre of the building, a unique variation that must have had an impact on how these features were used.
The WW2 Look Out Post is well preserved with an intact roof and a small internal fireplace with a chimney. As with the nearby trigonometry pillar this site reuses the signal station location because of its excelent visibility in all directions.