Monument record LCS 125 - World War II anti-invasion coastal defences.

Second World War anti-invasion coastal defences are visible as structures and earthworks on aerial photographs from 1940 onwards at Sizewell, Leiston (S1). Suffolk's coastal defences went through a number of developments during the war, and in this area the first defences to be visible on aerial photographs are composed of a length of barbed wire and a pillbox. The barbed wire ran for approximately 1 kilometre from circa TM47516420 to circa TM47606333, and formed a line of defence additional to the beach scaffolding and anti-tank cubes that were already in place. It is a continuation of a line of barbed to the north, recorded as TM19499. From 1941 two additional lengths of barbed wire can be seen, the first branching off the primary length of wire at circa TM64576396 to form a roughly rectangular enclosure, and the second bearing off to the north-west for approximately 120m from circa TM47486395 (S2, S3). The pillbox is visible positoned on the higher ground overlooking the beach at circa TM47626402. In October 1945 photographs, a structure and probable foundations of a group of additional structures are visible at circa TM47486376 (S4). As no structures are visible in 1943, and only foundations of most of the group are visible by October 1945, it seems likely that they were military in nature. It is not possible to be any more specific from the photographic evidence, but it is possible that they were related to the Heavy Anti-aircraft Artillery site immediately to the west, that appears and is dismantled within the same time frame. Two slit trenches, both circa 17m in length are also visible, located at circa TM47556340 and TM47506368. Most of the 'soft' defences have been removed by October 1945, but the pillbox and the northernmost trench is still visible in 1962 (S5). By 1973 they are no longer visible, possibly due the encroaching construction of Sizewell power station (S6).