During the Second World War, military defences were constructed at Titchwell. The drainage of farmland behind the banks was stopped, reflooding the former marshland; zigzag ditches were dug, and pillboxes built into Old Lord's Bank. Between 1942 and 1945, the marsh was used by the Royal Tank Regiment; an armoured fighting vehicle gunnery range was established and new banks were constructed for firing practice, with targets set at intervals. Some of the still extant islands were built to hold "pop-up" targets, operated by cables from winches in a building whose foundations lie below Island Hide. Remains of the triangular concrete track used by the tanks also survive. Military activities continued after the war, with the Royal Air Force returning to Thornham Marsh between 1950 and 1959. Bombing practice was supervised from a control tower, which was demolished in 1962, leaving only a concrete structure opposite the end of Titchwell's west bank. The remains of two Second World War Covenanter tanks, probably used as targets, are sometimes exposed at low tide.