Solomon Islands is a sovereign country consisting of a large number of islands in Oceania lying to the east of Papua New Guinea and northwest of Vanuatu and covering a land area of 28,400 square kilometres (11,000 sq mi).The country's capital, Honiara, is located on the island of Guadalcanal.ollowing the independence of neighbouring Papua New Guinea from Australia in 1975, the Solomon Islands gained self-government in 1976. Independence was granted on 7 July 1978. The first Prime Minister was Sir Peter Kenilorea, and Solomon Islands retained the Monarchy.