The Oliver Hill Battery is a significant heritage site and an icon of the home defence of Australia during World War II. It was one of seven similar gun emplacements built between 1937 and 1945 to defend major Australian ports from bombardment by warships. The main feature at each of these batteries was a pair of 9.2 inch guns, which could fire an armour piercing shell to a distance of 28 kilometres. By 1960, all of the batteries had become obsolete and were closed down. Oliver Hill is the only intact emplacement of its type left in Australia. Whilst the others were stripped of their guns, the then Rottnest Island Board was able to arrange with the Department of the Army to have the guns at Oliver Hill left in situ as historic site for island visitors. Apart from the gun emplacements, Oliver Hill houses underground tunnels, railway lines and paths and remnant coastal defence system structures. It is a 36 hectare site situated three and a half kilometres from the Settlement, in the centre of Rottnest Island. Guided tours are available and there is also a self-guided walk trail.
