Aberdeen (the Granite City) earned its reputation as the "energy capital of Europe "for its significant involvement in the Oil and Gas industry over the last 40 years. Many of the industry key players have a considerable presence in the City and use it as a base for work in the North Sea and beyond. Aberdeen has the largest heliport in the world and an important service ship harbour port serving offshore oil rigs, Aberdeen is often called the "Oil Capital of Europe". The number of jobs created by the energy industry in and around Aberdeen has been estimated at over half a million. The majority of the largest oil fields in the UK sector of the North Sea were found in the waters to the north and east of the Scottish mainland, with the more northerly fields found to the east of the Orkney and Shetland islands. Now, the city is gearing up for the next – and potentially most critical – phase of its evolution, using its proven oil and gas infrastructure and expertise to become a world leader in renewable energy. Significant knowledge and experience in offshore project management, underwater cables and foundations, semi-submersibles, moorings, autonomous vehicles and robotics is transferable and essential to the commercial-scale success of offshore wind and other offshore renewable energy.