Located six miles east of downtown Zanesville, Ohio, is the tiny, two-runway Zanesville Municipal Airport. The facility first started operations in 1947 and today offers passenger flights and charter flights as a general aviation facility. Though it may seem unassuming, the airport has the unique claim to fame of having the last IATA airport code in alphabetical order. As of 2023, nothing is designated after Zanesville's ZZV.

Flying from AUS-TRI-ANS takes you from Austin, Texas, to the Tri-Cities Airport of Blountville, Tennessee, and finally Andahuaylas, Peru. Flying PER-CHA-NCE hits Perth, Australia; Chattanooga, Tennessee; and Nice, France. AMS-TER-DAM appropriately starts in Amsterdam, the Netherlands, and then goes to Terceira Island in the Azores before heading to Damascus, Syria. There are no IATA airport codes for ICE or QUA, although KES takes you to Kelsey in Manitoba, Canada.

India’s Kolkata International Airport uses the IATA code CCU. Those letters come from when the city's name was spelled Calcutta, though that is no longer the case. In 2001, the city renamed itself to better represent its pronunciation in the local Bengali language and to help rid the country of its former English colonial ties.

During the early days of airport codes, the U.S. Navy reserved "N" as the first letter for its facilities. NPA, for example, is the Navy training airport in Pensacola, Florida. This has caused some other airports to settle for less-than-ideal codes. Newark International Airport, for instance, has to use the IATA code EWR.

DAD is the official code for Da Nang International Airport in Vietnam. COW serves Chile's small Coquimbo Airport. FUN is the code for Funafuti International Airport in the capital city of Tuvalu, a Polynesian island nation. With the large (and growing) number of airports in the world, many of the best three-letter words have already been claimed, but, for now, YOU is not an official airport code.

While Yuma, Arizona, is not particularly known for its food, it does have one of the tastiest-sounding airport codes in the country: YUM. Yuma International Airport is operated as a civilian airport in conjunction with the U.S. Marine Corps, who instead use the code NYL to identify it.

Willow, Alaska, may be a small city, but, like Lovelock, Nevada, it has one of the more exciting airport codes in the world. Its assigned IATA code is WOW, but visitors to the airport may not be very impressed — the small, single-runway airport handles mostly general aviation flights.

There are a number of unintentionally amusing IATA codes, from DUD (Dunedin, New Zealand) to SUX (Sioux City, Iowa) and UMM (Summit, Alaska). That list also includes LOL for Derby Field in Lovelock, Nevada. The general aviation facility is located in northwest Nevada.

In 1964, the Federal Aviation Administration and IATA performed a rare airport code swap for one of New York City's airports. Formerly known as Idlewild (IDL), the airport was renamed after the late President John F. Kennedy and was assigned the new code JFK. At that time, the letter J had previously been reserved for heliports, but officials decided that JFK was too logical a code to pass up.

Though Cincinnati/Northern Kentucky International Airport (CVG) primarily serves the greater Cincinnati area, its official airport code references another city. When the airport was originally founded, Covington, Kentucky, was the largest nearby city, and CVG took its call sign from that city. Today, CVG offers nonstop passenger service to more than 50 destinations.

Beijing has two massive international airports to serve nearly 100 million passengers per year. Beijing Capital International Airport (PEK) and Beijing Daxing International Airport (PKX) both take their international airport codes from the city of Beijing's former name, Peking. PEK is the busiest airport in Asia and the second busiest in the world, while newer PKX (opened 2019) claims the title of the largest single-structure airport in the world.

In 2001, New Orleans renamed its airport Louis Armstrong New Orleans International Airport in honor of the 100th anniversary of the jazz great's birth. Prior to that, it was called New Orleans International Airport, but originally it was Moisant Field — after John Moisant, a daredevil pilot who died in a plane crash at the site in 1910. Its airport code, MSY, still reflects this original designation.

YYZ is the code for Toronto Pearson International Airport, which serves Canada’s largest city by population and the capital of the province of Ontario. The airport is named after Lester B. Pearson, who served as the 14th prime minister of Canada from 1963 to 1968. In 2022, Pearson Airport handled 34.7 million passengers. Next on the list was Vancouver (YVR), with 18.6 million passengers.

With more than 18 million annual passengers, Portland International Airport accounts for roughly 90% of passenger air travel in Oregon. Originally the airport's code was just "PD," but when airports switched to three-letter codes in the late 1940s, they had to add a third letter, so they chose "X." LAX in Los Angeles has a similar story.

The largest international airport serving France's capital city is Paris-Charles de Gaulle Airport (CDG), which is named for the leader of the French resistance in World War II. Orly Airport (ORY) was previously Paris' main airport until the construction of CDG in the 1970s. Finally, 55 miles northwest of the city is Beauvais Airport (BVA), which has become the gateway to Paris for many budget airlines.

HEL is the official airport code of Helsinki-Vantaa Airport in Helsinki, Finland. The busiest airport in the nation, HEL is also the main hub for Finland's flag carrier, Finnair. Vantaa Airport was originally built for the 1952 Summer Olympics but today it handles more than 20 million passengers annually. Given the frequently harsh winter conditions in Finland, during an icy storm it is quite possible for HEL to freeze over.

Usually, an airport code is an abbreviated version of the city's name — for example, DEN for Denver and MIA for Miami. But that isn’t the case for Orlando. The city’s airport used to be called McCoy Air Force Base, which is where it got the MCO airport code — but some Orlandoans joke that it actually stands for Mickey's (Mouse, if you were wondering) Corporate Office.

IATA (International Air Transport Authority) issues three-letter codes to identify airports around the world. Chicago’s O'Hare International Airport was previously named Orchard Field Airport and took its code, ORD, from the nearby community of Orchard Place. It kept that designation even after the airport was renamed in 1949 for Edward "Butch" O'Hare, a World War II naval aviator.

Ronald Reagan Washington National Airport serves the Washington, D.C., area, hence the "DC" in its airport code DCA. Opened in 1941 as Washington National Airport, it was renamed in 1998 after the 40th U.S. President Ronald Reagan. While it’s located closer to the city center, Reagan Airport sees fewer passengers than Washington Dulles International Airport (IAD), which handles the vast majority of international flights to the region.

If you’ve ever booked flights to Vancouver (YVR), Ottawa (YOW), or Montreal (YUL), you may have noticed a consistent theme: All Canadian commercial airport codes begin with the letter “Y.” Before the formation of the International Air Transport Authority, Canada identified its weather towers with two-letter call signs. As air travel expanded, if an airport had a weather station nearby, a "Y" for "yes" was prepended to its existing code, and carried these over when IATA formed.

There are many airport codes around the world that end with the letter “X.” The “X” first appeared when airports changed from two-letter National Weather System (NWS) city codes to the three-letter IATA system in the 1930s. The “X” was simply added as an arbitrary letter at the end of these codes. Los Angeles International Airport, for example, went from LA to LAX.