A new study published by Routes has revealed the world’s busiest passenger air routes and—spoiler alert—it’s not in the United States.

With more than 13 million people flying just 279 miles between Seoul’s Gimpo Airport to popular Jeju island off the coast of the Korean Peninsula is the most in-demand air route in the world.

The route has around 180 scheduled flights per day, which means there is one flight every eight minutes taking off, transporting travelers to the island.

In 2017, 13,460,305 passengers flew between Seoul and Jeju, an increase of 9.4 percent.

The second busiest air route was between Melbourne, Australia, to Sydney Kingsford Smith Airport.

While it’s correct to be surprised that the title of world’s busiest air route is not in the U.S., which is the world’s largest aviation market, Routes found that air services in the Asia-Pacific region dominate the top 100 busiest routes by passenger numbers, accounting for more than 70 percent of the total.

The busiest international air route connects Hong Kong and Taiwan. The route between Taiwan’s Taoyuan International Airport and Hong Kong International Airport also holds claim to the title of eighth most popular overall, with 6,719,029 passengers flying the 498 miles in 2017.

The fastest-growing route is in Thailand. The route that links Bangkok Suvarnabhumi to Chiang Mai is the fastest-growing route in the top 100. The route showed growth of 36 percent year-over-year with nearly 2.4 million passengers.

“This research backs up forecasts that the Asia-Pacific region will be the biggest driver of passenger demand over the next 20 years. Such staggering aviation growth means it is the perfect time for World Routes to return to China,” Steven Small, brand director of Routes.

“The event will bring together senior decision makers from across the world to plan new air services and discuss increasing the frequency and capacity of the existing routes that are popular with passengers. The negotiations in taking place in Guangzhou could pave the way to the busiest routes of the future,” added Small.

The top 10 busiest scheduled passenger routes in the world:

—Jeju - Seoul Gimpo (CJU-GMP)

—Melbourne - Sydney Kingsford Smith (MEL-SYD)

—Sapporo - Tokyo Haneda (CTS-HND)

—Fukuoka - Tokyo Haneda (FUK-HND)

—Mumbai - Delhi (BOM-DEL)

—Beijing Capital - Shanghai Hongqiao (PEK-SHA)

—Hanoi - Ho Chi Minh City (HAN-SGN)

—Hong Kong - Taiwan Taoyuan (HKG-TPE)

—Jakarta - Juanda Surabaya (CGK-SUB)

—Tokyo Haneda - Okinawa (HND-OKA)

The top 10 busiest scheduled international routes in the world:

—Hong Kong - Taiwan Taoyuan (HKG-TPE)

—Jakarta - Singapore Changi (CGK-SIN)

—Hong Kong - Shanghai Pudong (HKG-PVG)

—Kuala Lumpur - Singapore Changi (KUL-SIN)

—Bangkok Suvarnabhumi - Hong Kong (BKK-HKG)

—Dubai - London Heathrow (DXB-LHR)

—Hong Kong - Seoul Incheon (HKG-ICN)

—Hong Kong - Singapore Changi (HKG-SIN)

—New York JFK - London Heathrow (JFK-LHR)

—Hong Kong - Beijing Capital (HKG-PEK)

The top 10 fastest-growing scheduled air routes in the top 100:

—Bangkok Suvarnabhumi - Chiang Mai (BKK-CNX)

—Seoul Incheon - Kansai International (ICN-KIX)

—Jakarta - Kuala Lumpur (CGK-KUL)

—Delhi - Pune (DEL-PNQ)

—Chengdu - Shenzhen Bao'an (CTU-SZX)

—Hong Kong - Shanghai Pudong (HKG-PVG)

—Bangkok Suvarnabhumi - Phuket (BKK-HKT)

—Jeddah - Riyadh King Kalid (JED-RUH)

—Jakarta - Kualanamu (CGK-KNO)

—Kolkata - Delhi (CCU-DEL)