The structure is a Martello tower, one of those thick-walled coastal fortifications built in large numbers during the Napoleonic era, but this one served a double purpose. For a brief and anxious period in the early nineteenth century, it was also a signal station, part of a chain of watchtowers strung along the Irish coastline, waiting for a French invasion fleet that never came.

The tower was under construction in 1805, when the threat of a French landing was taken seriously enough that the British Board of Ordnance built more than eighty such stations across Ireland, forming a continuous chain from Malin Head in Donegal to Dublin Bay. At Baginbun, the signal crew lived inside the tower itself, and the only thing added specifically for the station's communications role was a signal mast, erected by 1805. Signalling between stations was carried out using a naval signal post, a system of flags and visual codes familiar from the fleet. The nearest neighbouring stations were at Hook Head Lighthouse to the south-southwest, visible on a clear day at roughly nine kilometres, and at Crossfarnoge near Kilmore Quay, about sixteen kilometres to the east, though that station is now demolished. The whole network was abandoned by the mid-1810s once the likelihood of French invasion receded. The tower itself sits within a sub-rectangular earthen enclosure roughly 130 metres by 110 metres, open towards the coast to the south-southeast, and commands unobstructed views in every direction. That outlook was the entire point. The two flat-roofed single-storey additions now attached to the east and west walls of the tower are a later intrusion; they do not appear on any Ordnance Survey maps up to and including the 1921 edition, and were most likely added after 1947, when the tower was sold into private ownership and converted into a residence.

The site also sits in unusually layered historical company. Around 275 metres to the east lies a coastal promontory fort at the tip of Baginbun Point, and roughly 240 metres to the northwest are the remains of linear earthworks thrown up by Anglo-Norman forces in 1170, one of the earliest physical traces of the Norman arrival in Ireland. The signal tower, the medieval earthworks, and the prehistoric fort occupy the same narrow headland, each generation finding the same commanding ground useful for its own reasons.