Sound mirrors or acoustic mirrors are huge concrete structures that were designed as an early warning system for Britain. The purpose behind this magnificent creation was to detect enemy aircraft. Three designs of 6 metres, 9 metres, and 60 metres were made and all of them can be seen in Great stone, located in the north east side of the Dungeness Nature Reserve. They were developed by Dr. William Sansome Tucker.
Also called the ‘listening ears’, the mirrors were helpful during wars. Built during the late 1920s, the sound mirrors were part of the British national defence strategy. They did work well, and detected slow moving enemy aircraft before they came into sight. In fact, they were able to give a fifteen-minute warning of an approaching aircraft.
However, sound mirrors were outdated with faster flights coming into use. Later, radars were developed. Today, they remain as preserved monuments with many visitors throughout the year.