These milefortlets and intervening stone watchtowers extended from the western end of Hadrian's Wall, along the Cumbrian coast and were linked by a wooden palisade.

Aerial photographs show a square platform about 50 metres wide surrounded by ditches.

The original defence was a turf rampart 7 metres wide surrounded by a v-shaped ditch.

[1] Each milefortlet had two associated towers, similar in construction to the turrets built along Hadrian's Wall.

There was a distinct green mound at the approximate location of Tower 1A, but it was removed with the shingle for road building in the 1960s.