San Diego International Airport — San Diego, United States

Wedged between downtown San Diego's skyline and the waters of San Diego Bay, SAN operates as the busiest single-runway commercial airport in the United States, a distinction that produces one of the more memorable approach paths in American aviation as aircraft descend low over the city before touching down. The airport carries the nickname Lindbergh Field, honoring Charles Lindbergh, whose Spirit of St. Louis aircraft was built locally by Ryan Airlines in 1927 and completed early test flights from the site before his historic transatlantic crossing. San Diego's mild year-round climate, naval installations, and biotechnology sector all generate steady air travel demand, even as SAN's cramped urban footprint leaves little room for the kind of expansion enjoyed by newer airports built farther from city centers. Downtown hotels, Balboa Park, and the city's famous zoo sit only minutes away, making SAN unusually convenient for visitors compared with many major American airports elsewhere.