Ketchikan International Airport — Ketchikan, United States

Ketchikan International Airport sits on Gravina Island in southeast Alaska, directly across a narrow channel from the city of Ketchikan, which it serves. Because the airport and the town lie on separate islands, travelers reach the terminal by a short ferry across the Tongass Narrows, an unusual arrangement born of the region's rugged, water-cut geography. At an elevation of 89 feet, the single runway stretches about 7,500 feet, receiving jet service that links this southernmost Alaskan city to Seattle and other points. Ketchikan is a busy cruise and fishing town at the edge of the Tongass National Forest, and the KTN code marks a gateway where the surrounding sea shapes even the way passengers cross to their flights.