Courchevel International Airport (Courchevel, France)

Background:
Getting to the iconic ski resort of Courchevel requires navigating the formidable French Alps before making a hair-raising landing at Courchevel International Airport. The runway is about 1700 feet long, but the real surprise is the large hill toward the middle of the strip.
Why It’s Unique:
“You take off downhill and you land going uphill,” Schreckengast says. He adds that the hill, which has an 18.5 percent grade, is so steep that small planes could probably gain enough momentum rolling down it with no engines to safely glide off the edge. Landing at Courchevel is obviously no easy task, so pilots are required to obtain certification before attempting to conquer the dangerous runway.

Congonhas Airport (Sao Paulo, Brazil)

Background:
Most major cities have an airport, but rarely are they built just 5 miles from the city center, especially in metropolises like Sao Paulo. Congonhas’ close proximity to downtown can be attributed in part to the fact that it was completed in 1936, with the city experiencing rapid development in the following decades.
Why It’s Unique:
While having an airport only 5 miles from the city center may be a convenience for commuters, it places a strain on both pilots and air traffic control crews. “It becomes a challenge in terms of safety to just get the plane in there,” Schreckengast says. “Then you throw on noise restrictions and these terribly awkward arrival and departure routes that are needed to minimize your noise-print and it becomes quite challenging for pilots.” Fortunately, Sao Paulo’s many high-rise buildings are far enough away from the airport that they aren’t an immediate obstacle for pilots landing or taking off.

Don Mueang International Airport (Bangkok, Thailand)

Background:
From a distance Don Mueang International looks like any other midsize airport. However, smack-dab in the middle of the two runways is an 18-hole golf course.
Why It’s Unique:
Schreckengast, who has worked on consulting projects at this airport, says one of the major problems is that the only taxiways were located at the end of the runways. “We recommended that they build an additional taxiway in the middle, from side to side, and they said ‘absolutely not, that will take out a green and one fairway.’” The airport and the course were originally an all-military operation, but have since opened up to commercial traffic. Security threats, however, have limited the public’s access to the greens.

Madeira International Airport (Madeira, Portugal)

Background:
Madeira is a small island far off the coast of Portugal, which makes an airport that is capable of landing commercial-size aircraft vital to its development. This airport’s original runway was only about 5000 feet long, posing a huge risk to even the most experienced pilots and limiting imports and tourism.
Why It’s Unique:
Engineers extended the runway to more than 9000 feet by building a massive girder bridge atop about 200 pillars. The bridge, which itself is over 3000 feet long and 590 feet wide, is strong enough to handle the weight of 747s and similar jets. In 2004, the International Association for Bridge and Structural Engineering selected the expansion project for its Outstanding Structure Award, noting that the design and construction was both “sensitive to environmental and aesthetic considerations.”

Gibraltar Airport (Gibraltar)

Background:
Between Morocco and Spain sits the tiny British territory of Gibraltar. Construction of the airport dates back to World War II, and it continues to serve as a base for the United Kingdom’s Royal Air Force, though commercial flights land on a daily basis.
Why It’s Unique:
Winston Churchill Avenue, Gibraltar’s busiest road, cuts directly across the runway. Railroad-style crossing gates hold cars back every time a plane lands or departs. “There’s essentially a mountain on one side of the island and a town on the other,” Schreckengast says. “The runway goes from side to side on the island because it’s the only flat space there, so it’s the best they can do. It’s a fairly safe operation as far as keeping people away,” he says, “It just happens to be the best place to land, so sometimes it’s a road and sometimes it’s a runway.”

Kansai International Airport (Osaka, Japan)

Background:
Land is a scarce resource in Japan, so engineers headed roughly 3 miles offshore into Osaka Bay to build this colossal structure. Work on the manmade island started in 1987, and by 1994 jumbo jets were touching down. Travelers can get from the airport to the main island of Honshu via car, railroad or even a high-speed ferry.
Why It’s Unique:
Kansai’s artificial island is 2.5 miles long and 1.6 miles wide—so large that it’s visible from space. Earthquakes, dangerous cyclones, an unstable seabed, and sabotage attempts from protestors are just some of the variables engineers were forced to account for. As impressive as the airport is, Stewart Schreckengast, a professor of aviation technology at Purdue University and a former aviation consultant with MITRE, cautions that climate change and rising sea levels pose a very real threat to the airport’s existence. “When this was built, [engineers] probably didn’t account for global warming,” he says. “In 50 years or so, this might be underwater.”