shivering sands army fort [u7] was a maunsell army fort built near the thames estuary for anti-aircraft defence. it is made up of several once interconnected towers north of herne bay and is 14.8 km (9.2 miles) from the nearest land. they can be viewed from shoeburyness east beach on clear days. the shivering sands fort was the last of the thames estuary forts to be constructed, and was grounded between 18 september and 13 december 1943.