The Henry Head Battery is located on the northern side of the entrance to Botany Bay at Henry Head. The battery was constructed on an unfenced headland between 1892 and 1895 and operated until 1910 when it was closed down. The battery and observation posts was re-utilised during World War Two to defend against approaches to Botany Bay. The battery consisted of two disappearing guns, ammunition storage and observation posts. The underground bunker and tunnel complex consisted of vaulted ammunition storage rooms with double walls and ceilings. The doubling-up of walls and ceilings was a preventative measure meant to stop the walls from collapsing in the event of a direct hit. The battery is currently not in use. The white tower on the battery is the Endeavour Tower, not a lighthouse as such, but a red marker light nonetheless.