Milecastles

Milecastles were small, fortified structures built at intervals along Hadrian's Wall in Roman Britain. They were constructed every Roman mile, hence the name, and were about one-third the size of a typical fort. These structures served as barracks for a small garrison of soldiers, typically around 20-30 men, and acted as bases for patrols and for controlling movement along the wall.

Each milecastle typically consisted of a rectangular stone enclosure with a gateway at each end, one facing north and one facing south. Within the enclosure were buildings, often including barrack rooms, a granary, and possibly a commander's house. The garrisons stationed at milecastles were responsible for maintaining the section of the wall in their vicinity, collecting tolls, and apprehending any unauthorised individuals attempting to cross.

The exact number and precise function of all milecastles are still debated by archaeologists. Some may have been permanently garrisoned, while others might have been used more intermittently. They represent a key element of the defensive and logistical system that Hadrian's Wall represented for the Roman Empire.