BP opened an exploration office in Stavanger, Norway in 1974 and made several discoveries in the North Sea, including the Ula, Valhall, and Gyda fields. In 1975, the Forties field began production, with Queen Elizabeth II pushing the button to mark the occasion. Also in 1975, BP discovered four fields in one year - Rhum, Andrew, Magnus, and Clair. In 1978, the first oil reached Sullom Voe terminal in the Shetland Islands, which BP had constructed to process oil from fields in the east of the islands.