Betio, the western tip of Tarawa Atoll, was one of the most heavily fortified positions of the Pacific War and the site of the brutal Battle of Tarawa in November 1943. Walking around the islet today you still find Japanese bunkers, coastal gun emplacements with their long-barrelled British-made naval guns intact, command pillboxes scarred by shellfire, and the rusting wreckage of landing craft on the reef flats at low tide. The principal Marine memorial sits near the old causeway, and Japanese and Korean memorials are scattered across the island.
The whole islet is the battlefield — there is no marked trail. Hire a local guide in Betio or arrange one through your hotel; they know which gun positions to find, the stories behind them, and which scrap of beach corresponds to which Marine company's landing. Bring water, sun cover, and good shoes. It is hot, exposed, and slow walking, but it is one of the most affecting battlefield visits anywhere.