Horn Island's old airfield, gun positions, slit trenches, and scattered wartime remains tell the story of a northern base that was bombed repeatedly in 1942 and 1943. The sites are spread out and often understated, so a guided tour is much better than wandering around alone.
The strongest parts are not grand monuments but the small physical traces: earthworks, concrete, rusting fragments, and the sense of how exposed the island was between Australia and New Guinea.