This is the largest of the three mirrors and is 200 feet long..
They were built between 1928 and 1935 as part of Britain's national defence strategy. The low lying Romney Marsh was well suited for the placement of the Mirrors which were designed as early warning systems to pick up the sounds of approaching enemy aircraft coming over the English Channel. But the innovative technology was soon superseded by the invention of radar before the start of World War II. However, time spent constructing the Sound Mirrors was not wasted, as the technology used to create these led to developments of other aircraft detection systems.
