The Solomon Islands are an archipelago of volcanic islands located north of equator in the central-western Pacific Ocean, in Melanesia, to the east of Papua New Guinea and to the north of Vanuatu Islands. The Solomon Islands are an independent parliamentary monarchy under the British Commonwealth, the capital is Honiara on the island of Guadalcanal. The islands stretch for about 1,600 km north-west south-east, include thirty major islands and several smaller islands and atolls, the main island Guadalcanal (6,470 sq km), home of the state capital, the city of Honiara, is an island of volcanic origin, it has the highest peak of the archipelago, Mount Popomanaseu (2,332 metres). Other islands are Santa Isabel (4,662 sq km), Malaita (3,885 sq km), Choiseul (3,837 sq km), New Georgia (3,368 sq km), and Makira (San Cristobal, 3,125 sq km), among other islands there are the atolls of Rennell and Ontong Java, the Santa Cruz islands, Rennell, Bellona and the isolated islands of Tikopia, Anuta and Fatutaka. The archipelago contains several still active volcanoes, among them the most active volcanoes are the Tinakula (851 metres) and Kavachi an underwater volcano, south of the island of Vangunu. At the base of the islands economy is agriculture, especially the cultivation of palm trees (copra) and oil, fairly well developed are breeding (cattle, pigs), fishing (tuna) and the exploitation of forest resources. The subsoil resources have extensive deposits of bauxite and phosphates.