Biak (1898 sq km) is one of Papua’s biggest offshore islands. It’s a relaxed and friendly place with good snorkelling and diving. It was once a popular destination with foreign travellers to Papua but today has been rather eclipsed by the Raja Ampat Islands.
Biak saw fierce fighting in WWII, with about 10,000 Japanese and nearly 500 Americans reported killed in the month-long Battle of Biak (1944). There are several historic sties worth visiting, including a cave that the US dropped a bomb on, killing 3000 Japanese soldiers, and a sunken US seaplane that's now home to lots of fish and coral.