On Sunday, March 13, a small walking group ventured to Greatstone for an open day to see the sound mirrors, also known as acoustic mirrors or listening ears. It took longer than anticipated to get there through some beautiful nature, but it was well worth it once the mirrors came into view, surrounded by water.
They can only be reached over a small swing bridge which is only opened on special visiting days. A Royal Society of the Protection of Birds (RSPB) volunteer was waiting to impart the history to an interested audience. The three concrete structures, ranging in size from 20 to 200 feet were built between 1925 – 1935, the first two leading eventually to the biggest beautifully curved wall as part of a defence strategy. It was decided that low lying Romney Marsh was ideal to place the structures on, to serve as an early warning system of an approaching aircraft coming across the English Channel.
The technology was hailed as ahead of its time but it did not last long as radar was invented soon afterwards, before the second world war. However the principle of the design was not deemed wasted as the construction helped further developments of the enemy aircraft detection system.
The seventy hectare site was handed over by Camex in 2015 to the RSPB to be run as the Dungeness Nature Reserve. If you are interested about further opening days in 2022 please email soundmirrors@rspb.org.uk.
Image Credits: Heidi Foster , Rachel Calvert .