The more than 150 islands constitute three main groups: Tongatapu (seat of the capital) in the south, Vavau in the north, and Haapai in the center. Several of the islands are volcanic, with active craters, but most are coral atolls. The climate is tropical. Most of the people are Polynesian and Christian (primarily Methodist). Tongan, a Polynesian language, and English are spoken. Squash, coconuts, bananas, vanilla beans, cocoa, coffee, ginger, and black pepper and kava are grown, and there is fishing. Tourism and remittances from Tongans working abroad are also important. Vegetables, vanilla beans, seafood, and kava are exported, while foodstuffs, machinery and equipment, fuels, and chemicals must be imported. The main trading partners are Japan, the United States, and New Zealand.