Milecastle 69 is thought to lie near the small village of Grinsdale in the civil parish of Beaumont.

[1] It probably lies somewhere between Sourmilk Bridge and the buildings of Park Farm to the west of Grinsdale.

[1][2] A survey of 1858 noted a quantity of foundation stones close to the stream at Sourmilk Bridge, but since a map of 1746 shows a mill on the east bank of Sourmilk Bridge, it is likely that the stones came from the demolished mill.

Turret 69A probably lies midway between Sourmilk Bridge and where Holme Lane runs closest to the Wall.

[1] Turret 69B is probably located beneath the site of St Andrew's Church in the village of Kirkandrews-on-Eden.