Lower Keep Battery was built inside Elisabeth Castle between 27th November 1902 and 7th April 1904. The total cost of building the battery was £2167 and it mounted two 4.7-inch Q.F. BL guns. The magazine was built underground to the rear of the A (No.1) gun emplacement and held 1000 rounds. The National Archives WO 78/4908.
This gun platform originally held three 32-pdr SB guns, two 8-inch shell guns and two 10-inch Mortar . (The National Archives MPHH 1/679, 1849).
In about 1875 two 7-inch RML guns were mounted at Upper Keep Battery, with one of the original guns on display in the Castle Museum. The Upper Keep Battery overlooks the Lower Keep Battery.
The 4.7-inch battery remains relatively intact, with the two gun mounts still in place.