Palma de Mallorca Airport — Palma de Mallorca, Spain

Few European airports swing as hard between seasons as Palma de Mallorca Airport, universally known by its code PMI, which ranks among Spain's busiest and, during peak summer weeks, handles a volume of flights that rivals some of the continent's largest hubs. Officially named Son Sant Joan after the district southeast of Palma where it sits, the facility operates one sprawling terminal that expands to absorb the crush of charter and low-cost carriers ferrying sunseekers to the Balearic Islands each summer. Winter traffic drops off sharply, creating one of the more dramatic seasonal contrasts among major European airports. Beyond tourism, PMI supports a resident island population that multiplies several times over during high season, and its runways sit close enough to the Mediterranean that arriving flights offer clear views over the bay below. German and British travelers have long formed the backbone of its passenger base, reflecting decades of package-holiday demand for Mallorca's beaches and nightlife.