The island is crossed from north to south by a high mountain range that reaches a maximum altitude with Mount Yu Shan (3,952 metres), along the east coast the mountains, that reach the coast, are high and rocky, instead the west coast, densely inhabited, is low and flat. The economy of Taiwan is one of the most developed in Asia, agriculture produces rice, sugar cane, tobacco, spices, citrus fruits, tea, coffee, tomatoes, fruit (peaches, pears), sweet potatoes, corn and soybeans; modest farming (pigs and poultry). The rich forests produce valuable essences (bamboo, camphor, sandalwood, cedar and rattan), fishery is well developed and organized (tuna, sword fish, sharks, and mackerel) main fishing ports are those of Keelung and Kaohsiung. Among the resources of the subsoil are extracted mainly coal, then silver, gold and sulphur, low extraction of oil and natural gas. The industry is the backbone of the economy of Taiwan, the manufacturing sector is highly developed, particularly electronics, information technology, shipbuilding, textiles, food (sugar, canning, breweries, tobacco), chemical, petrochemical and metallurgy.