27 km2) consists entirely of a raised, relatively flat-topped plateau of Pleistocene, coralline limestone, which rises up to 170 m above sea level (asl.)

The islands are the remnants of a stratovolcano which collapsed to form a caldera.

Former Prime Minister of Papua New Guinea Sir Julius Chan and Sumsuma, the leader of the Rabaul Strike of 1929 and Papua New Guinea's First Unionist are from the Tanga Islands.

Secret Societies practiced on the Islands are Sokapana, Tubuan and Ingiet.

Mask dances include Lor, Tedak and Kipong are performed during cultural occasions.