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 46 are known as Turret 46A and Turret 46B.
Turret 46A
Turret 46A has never been located, and its position has been calculated from the neighbouring milecastles. It may lie under the house or garden of Holmhead.
Turret 46B
Turret 46B has never been located, and its position has been calculated from the neighbouring milecastles. It may lie under a farm outbuilding.