A searchlight tunnel was dug into the cliffs during the late 19th century. The current searchlight emplacement was built in 1899. The light was used to track targets for the guns to aim at and for the remote detonation of mines.

Located high on clifftops overlooking The Needles, the Old Needles Battery was built during the 1860s to guard the approaches of the western Solent from encroachment by enemy ships. It was subsequently used for coastal defence in both the First and Second World Wars. Today it remains a Grade II listed site under the stewardship of the National Trust.