most populous island of Samoa, in the South Pacific Ocean. It lies across the Apolima Strait from the island of Savai'i to the west. Upolu is about 46 miles (74 km) long and 16 miles (26 km) across at its widest point, with an area of 432 square miles (1,119 square km). Its volcanic central mountain range reaches a maximum elevation of 3,608 feet (1,100 metres) at Mount Fito, in O Le Pupu-Pu'e National Park (1978). The island has a densely forested interior, fertile coastal soils, and a wet tropical climate; the endangered flying fox and several types of tropical birds are found there. The port of Apia, the main commercial and political centre, is on the northern shore. The island's products include electric components, beer, cigarettes, coconut creams and oils, copra, cacao, and taro. Pop. (1986), including adjacent islands, 112,228; (1998 est.) 115,000.