The walls still stand to nearly six metres in places, though the upper section came down in a winter storm in 1989 or 1990, sending a wide spread of rubble eastward across the hillside. The apertures for joist slots, a limestone-lintelled fireplace with sandstone-lintelled alcoves to either side, and traces of interior render still legible on the surviving walls give a surprisingly domestic quality to what was, in its day, a military installation.

The tower was built around 1806 by the British Board of Ordnance, at a moment when a French naval landing on the Irish coast was considered a serious possibility. Each station in the network used a naval signal post to communicate with its neighbours, passing warnings along the coast by line of sight. From Shivel Head, on a clear day, the tower on Saddle Hill to the north-north-east on Achill Island is visible roughly 12.6 kilometres away, as is the tower on Inishturk Island approximately 11.2 kilometres to the south-south-west. The threat had receded sufficiently by the mid-1810s that the whole system was abandoned. The tower at Shivel Head is a square two-storey structure of roughly coursed limestone and sandstone rubble, originally entered at first-floor level through a doorway on the west elevation, with the semi-basement level now partially infilled with soil. Within the enclosure wall that surrounds the site, the foundations of what may be a small hut survive to the west of the tower, and an oval lime kiln, a structure used for burning limestone to produce agricultural quicklime, sits in the south-west corner.

The site sits within a shallow north-south depression across the hilltop, with Knockmore Mountain blocking the view to the east and open sightlines in every other direction. Clare Island Abbey lies roughly 3.85 kilometres to the east-north-east, and a group of booley huts, seasonal shelters used historically during summer cattle grazing, occupy the lower south-western slopes of Knockmore about 828 metres away. A coastal promontory fort at a place called Doon, on a narrow peninsula at Strake, lies around 2 kilometres to the south-east, a reminder that this exposed western headland has drawn human attention, for very different reasons, across a long span of time.