Birmingham Airport, United Kingdom (BHX/EGBB)
The Birmingham Airport (formerly Elmdon Airport) opened on July 8, 1939. It served as a flight school and test center during World War II. Today the airport serves over nine million people a year with just a single runway. Its new control tower, which replaced Elmdon Airport's original one in 2012, stands 33 meters (108 feet) high. The cab, the tower section where the controllers work, has heated windows to evaporate water for better visibility.

Fort Worth Alliance Airport, Texas, United States (AFW/KAFW)
"Alliance" refers to the public-private partnership of the three entities responsible for designing and developing Fort Worth Airport: the Federal Aviation Administration (FAA), the city of Fort Worth, and Ross Perot Jr.'s company, Hillwood. It is the world's first 100 percent industrial airport—used for civil and military cargo, commercial, corporate, and other noncommercial flights. Situated on 485 hectares (1,198 acres), the airport's runway can accommodate the world's largest cargo planes. Albert Halff Associates designed the control tower, which was built in 1992. The cone-shaped feature, reminiscent of a bird's beak, hides the tower's microwave signal relay equipment.

Edinburgh Airport, Scotland, United Kingdom (EDI/EGPH)
Originally a military airport, Edinburgh Airport opened to commercial aviation in 1977. It is now Scotland's second largest airport after Glasgow. Edinburgh's new control tower took 15 months to complete and opened in 2005. It stands 57 meters (187 feet) high, which equals 12 double-decker buses stacked on top of one another. The exterior's crisscrossed, double-helix pattern is not just for aesthetics. It also functions as a system of drainage channels. The 9,216 zinc tiles were hand-installed and have aged naturally in the outside environment, reducing the need for maintenance.

Edwards Air Force Base, California, United States (EDW/KEDW)
Rogers Dry Lake in California's Mojave Desert served as the Muroc Bombing and Gunnery Range in the 1930s. During World War II, the site became a training base. Later, new and top-secret aircraft were tested here. Edwards Air Force Base is home to many aviation "firsts" and countless records, and it served as a landing site for the space shuttle. The airport tower has two High Rise Escape Systems (HRES) for air traffic controllers in the event of an emergency. Each HRES consists of a harness shaped like an over-sized pantsuit, and a descent device that lowers the evacuee safely to the ground.

Ronald Reagan Washington National Airport, Virginia, United States (DCA/KDCA)
In 1938, President Franklin Roosevelt chose Gravelly Point on the Potomac River as the site of a new airport for the nation's capital. Washington National Airport opened in June 1941. In 1997 a new tower was built in a post-modernist style. Designed by César Pelli and Associates, it stands 61 meters (201 feet) tall. It originally had a white dome on top that housed ground-radar equipment. However, buildings in nearby Crystal City, Virginia, caused a radar echo, or "ghost," so the dome was moved to a ground location on the airfield. Congress renamed DCA "Ronald Reagan Washington National Airport" in 1998.

Oslo Airport, Norway (OSL/ENGM)
Gardermoen is one of Norway's oldest airports. It served as a flight training center and an alternative to the Fornebu airport near Oslo. It was redeveloped and reopened in 1998 as Oslo's primary airport. Gudmund Stokke designed the metal, wood, and glass terminal. Displayed throughout the airport is art representing Norway's creative diversity. Carin Wessel used 30,000 meters (98,425 feet) of thread to create the impression of clouds and webs. Sidsel Westbo etched the glass walls with "sound showers" that make soothing sounds when passengers walk underneath them. Aviaplan won the design competition for the 92-meter (302-foot) control tower.

Stockholm-Arlanda Airport, Sweden (ARN/ESSA)
The Stockholm-Arlanda Airport control tower is probably one of the first to double as a wedding location, where couples can pay for a marriage ceremony. Designed by Gert Wingårdh, the 83-meter (272-foot) tower was completed in 2001. There are two control cabs, perched like birds atop the shaft. They symbolize Hugin and Minun, two ravens from Nordic mythology, who were sent out to watch over the world. On the black and white bands, Finnish artist Silja Rantanen superimposed 2,500 words from Antoine de Saint-Exupéry's classic 1929 aviation book Southern Mail.

Dubai International, United Arab Emirates (DXB/OMDB)
Dubai's airport began with a terminal, fire station, and single runway of compacted sand. It has steadily grown to emerge as one of the world's major airports. It now has two CAT III B instrument landing systems for low visibility conditions and runways large enough to handle the Airbus A380, the world's largest airliner. The 87-meter (285-foot) airport traffic control tower, with its buttressed center column and arched wings, resembles a futuristic avian sculpture. A multilevel control center crowns the tower, with Dubai Air Navigation Services operating from its perch.

Dubai World Central-Al Maktoum International Airport, United Arab Emirates (DWC/OMDW)
Dubai World Central Airport, also known as Al Maktoum International Airport, is the world's first purpose-built aerotropolis a new form of urban planning that places the airport at the center. The control tower, commissioned in 2010, stands 91 meters (299 feet) tall. A second tower, 300 meters (394 feet) tall, is also planned. The "flower" design concept is a minimal square "stem" flanked by four curved "petals." The petals fan out at the tower base to provide stability, and the "bloom" at the top supports the double-level control cab. Luminous gold-tinted glazing adorns the tower.

United Arab Emirates (AUH/OMAA)
This is the only tower in the world that takes the form of a crescent. At 109 meters (358 feet) tall, it stands between parallel runways. The crescent design stems from the area's maritime heritage. It represents the sail of a dhow boat, a cultural icon and welcoming symbol to visitors. Abu Dhabi International Airport opened in 1968 on an island just off the Arabian Peninsula. A new airport opened on the mainland in 1982. Some 126 million passengers have traversed its halls.

Abu Dhabi International Airport, United Arab Emirates (AUH/OMAA) 
Designed by the French architecture firm ADPI, this tower was completed in 2011 after only 629 days of work. At the peak of construction, 1,200 workers were on site 24 hours a day. More than 70 kilometers (44 miles) of cabling run up the central column, sandwiched between high-speed elevators that ascend to the 20th story in 55 seconds. The east and west facades are covered by ethylene tetrafluoroethylene panels, a transparent polymer material. They allow for interior sunlight during the day and provide a glowing effect at night.

LaGuardia Airport, New York, United States
LaGuardia's Art Deco Marine Air Terminal is one of the oldest terminals in the United States. Designed by William Delano under the New Deal Work Projects Administration, it opened in 1940. The 1964 tower was designed by Wallace K. Harrison, famous for his 1939 World's Fair sculptures, Rockefeller Center, Lincoln Center, and the United Nations headquarters. The New York Times referred to the whimsically designed tower as "a design for a giant ice cream cone." In 2010 a new tower superseded the old one. The upper section of the original 46-meter (150-foot) tower was removed because it obstructed the new tower's view.

Barcelona El-Prat Airport, Spain 1965
Barcelona's first airport, an airfield at El Remolar, opened in 1916. It relocated in 1918 to El-Prat. Initially used by the Aeroclub of Catalonia, it also became the base for the Spanish navy's fleet of airships. Barcelona El-Prat began commercial air service in 1927 and is now the second largest airport in Spain, after Madrid. It has undergone several transformations over the years. Two of its three towers are no longer in service. Designed by Eduardo Aguirre, this one from 1965 stands 15 meters (50 feet) tall.