Analysis of information sources in references of the Wikipedia article "Jeju City" in English language version.
Jeju, on the South Korean island of the same name, is not one of the country's 20 biggest cities. Yet the island's allure as a domestic tourist destination resulted in 9.9m passengers flying between Seoul and Jeju (in either direction) in 2011. This makes it the busiest airline route in the world, according to Amadeus, a company that provides technology to the travel industry.
