Maunsell Sea & Air Forts, Thames And Mersey Estuaries, UK
These wartime structures were erected during the Second World War in 1942 to slow down the invasion of the Axis on the United Kingdom. However, after the war ended, the structures were decommissioned in 1950. These forts were surrendered in 1958 but there are some of them which have stood the test of time.
