Aberdeen International Airport — Aberdeen, United Kingdom

For decades, Aberdeen has been known as Europe's offshore oil capital, and its airport reflects that identity more directly than almost any other in the United Kingdom, having long claimed the title of one of the world's busiest heliports thanks to constant helicopter shuttles out to North Sea platforms. Sitting at 215 feet above sea level in northeast Scotland, the airport runs a single fixed-wing runway alongside extensive helicopter facilities, a combination that sets it apart from typical regional UK airports. Aberdeen itself, built largely from local granite and nicknamed the 'Granite City,' grew wealthy on North Sea oil and gas from the 1970s onward, and the airport's fortunes have tracked the energy sector's ups and downs ever since. Passenger numbers dip when oil prices fall and workforce rotations slow, then recover as offshore activity picks back up. Beyond the energy industry, the airport also connects the Granite City to London and other UK hubs for business and leisure travel. Few airports anywhere tie their identity as closely to a single industry as Aberdeen does to North Sea oil.