Challenger Battery, Artillery battery in Garden Island, Western Australia.

Challenger Battery stands at Entrance Point, the north-west tip of Garden Island. Its rectangular magazine bunker has brick walls, concrete floors and roof, and a reinforced-concrete seaward wall dividing two storage sections. Two 155 mm gun mounts remain, each with a central concrete boss, mounting bolts and an outer traversing ring with recoil-stabiliser arms on a curved steel rail.

Built in 1942 as J Gun Battery, it was the first gun battery on Garden Island and part of the Fremantle Fortress. Two US-supplied 155 mm guns on Panama mounts were installed in early 1943 and operational by April, guarding Cockburn Sound and Challenger Passage. The guns were withdrawn in December 1944 and removed by 1963. It was listed on the Australian Commonwealth Heritage List on 22 June 2004.

The site reflects how Western Australia organized its coastal defense and the role of international military cooperation during wartime. You can see how the defensive infrastructure was built into the local landscape.

Challenger Battery sits at Entrance Point, the extreme north-west tip of Garden Island, within a working naval base. Public access to the island is limited and normally requires prior arrangement, so confirm current conditions before planning a visit. The site is recorded in the Australian Heritage Database.

The position was one of the earliest defensive structures built specifically during wartime operations on the island. This rapid response to military threats shows how urgent coastal security was for the region.