The Solomon Islands comprises over 900 islands that extend southeast from Papua New Guinea across the Coral Sea to Vanuatu. The largest islands are Guadalcanal, Malaita, New Georgia, Santa Isabel, Makira (San Cristóbal), and Choiseul. The majority of the islands are uninhabited.
Thickly forested mountain ranges, deep narrow valleys, and fast-flowing rivers characterize island interiors. Coastal belts feature mangrove swamps or coconut plantations. Coral reefs and lagoons surround individual islands. Some reefs are dying, and logging leads to deforestation on some islands. Earth tremors are frequent.