The entire peninsula is covered by a dense
tropical rainforest. Most of the peninsula consists of a
marshy plain, covered in
lowland rainforest. There are smaller areas of
montane rainforest in the Fakfak and Kumawa mountains along the peninsula's western edge. Together with the eastern region of Bird's Head Peninsula and offshore islands, the Bomberai Peninsula forms the Indonesian province of
West Papua (). The western part of the peninsula is part of
Fakfak Regency, the north belongs to
Teluk Bintuni Regency and the southeast to
Kaimana Regency. It is a wide peninsula that opens to the
Seram Sea, forming a wide bay,
Sebakor Bay, defined by two small peninsulas: • to the northwest is the
Onin Peninsula part of
Fakfak Regency, includes
Fakfak, the main town and port of the region. The
Fakfak Mountains reach 1619 m (5312 ft) elevation. Due to the facilities offered by the town of Fakfak, this part of the Bomberai Peninsula is the most visited. • to the southeast is the peninsula formed by the
Kumawa Mountains, whose south coast is bathed by the
Arafura Sea. It is a region little explored by europeans tourists and almost unknown to them. The region is historically called Sran and later Kowiai after the people and kingdom and the southern coast is part of
Kaimana Regency and its main town and port
Kaimana. To the north lie
Berau Bay and
Bintuni Bay, which separate the Bomberai Peninsula from the Bird's Head peninsula. Off the north coast are located the islands of Amutu Besar, Asap,
Arguni and Ugar. Opposite is the island of Panjang in Tamaruni Bay. Further south are
Samai Island and Sebakor Bay, which is protected from the offshore island of Karas by the Tamaruni Bay. Southeast beyond the Nautilus Strait () is
Adi Island. In the east, Kamrau Bay separates the peninsula from the rest of New Guinea. At its northernmost point lies the island of Freterenusu in the bay. Only narrow land bridges connect the Bomberai peninsula with the neighboring land masses. The Terumbu Karang Sehat Indonesia programme implemented by
Konservasi Indonesia has supported local marine protected-area management in the Bomberai area, including work on institutional and financing arrangements. == History ==