Milefortlet 13

Milefortlet 13 was a Milefortlet of the Roman Cumbrian Coast defences. 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. They were contemporary with defensive structures on Hadrian's Wall. The exact location of Milefortlet 13 is unknown, although two of the nearby turrets (Towers 13A and 13B) have been located and excavated.

• http://en.wikipedia.org/wiki/Milefortlet 13