Irregular plan concrete gun floor with centrally set steel holdfast for 4-inch Mk IX QF gun, enclosed by a low concrete wall. Magazine located in pre-existing, rectangular plan, limestone rubble, secondary flat reinforced concrete roofed structure.
Record derived from Defence of Britain Project (Record Number 12217)
Located on St Catherine's Isle (nprn 579), adjacent to 19th C. gun fort (nprn 268163).