[3] The city and Buka Island are separated from the northern tip of Bougainville Island by the deep, narrow Buka Passage, which varies in width from 980 to 3,000 feet (300 to 1,070 metres).

The elevation reaches to 1,634 feet (498 metres) in the hills in the southwest, and the interior of the island is densely forested.

Coral reefs fringe the south and west coasts, the latter deeply indented by Queen Carola Harbour.

The former, or "proper" capital of Bougainville, Arawa, was all but destroyed in 1990 as tensions reached a critical level in a civil uprising, which ended with the Bougainville Peace Agreement in 1998.

The Bougainville government intends to return the capital to Arawa in the future.