Siau

Siau is an Indonesian volcanic island in the Sangihe archipelago in North Sulawesi Province. It lies in the Celebes Sea, to the northeast of the island of Sulawesi and just north of Mindanao, Philippines. The island is part of the Sangihe Islands Regency and is the site of the regency's administrative center, Tahuna. Siau is known for Mount Karangetang (Api Siau), an active stratovolcano near the island's center, which has a long history of eruptive activity and ash plumes that have periodically affected nearby communities.

Population is concentrated along the coast around Tahuna and other small towns. The inhabitants belong to the Sangihe cultural group, who speak Sangihe languages such as Sangihe and Tahuna, and maintain traditional practices and crafts.

Historically, Siau was part of early spice and trade networks and later became part of the Dutch East Indies. After Indonesian independence, it became part of North Sulawesi Province as the Sangihe Islands Regency. The island's economy relies on agriculture, including spices and cacao, as well as fishing and small-scale commerce. Due to volcanic hazards and limited transport infrastructure, tourism remains modest but some visitors come for hiking and nature experiences around Mount Karangetang and coastal ecosystems.

Environmental and hazard issues include volcanic eruptions, earthquakes, and tsunamis associated with the region. Conservation and disaster preparedness are ongoing concerns for residents and authorities.