Milecastle 64 is located in Cumbria

Each milecastle on Hadrian's Wall had two associated turret structures. These turrets were positioned approximately one-third and two-thirds of a Roman mile to the west of the Milecastle, and would probably have been manned by part of the milecastle's garrison. The turrets associated with Milecastle 64 are known as Turret 64A (grid reference NY414585) and Turret 64B (grid reference NY411582). None of the turrets between Milecastles 59 and 72 were sought or identified prior to 1961, and the exact locations of turrets 64A and 64B have not been found.^[2]

• http://en.wikipedia.org/wiki/Milecastle 64