image creditBefore the application of radar became a reality a number of experimental early warning systems were developed by the British military. One which showed the most promise - as it actually worked - were the acoustic mirrors built at Denge on the south coast of England.
Quickly superseded by radar they were abandoned but still remain at their post, obsolete concrete leviathans on an island in the middle of a nature reserve, reminders of a dangerous time in European history.
