If you're surprised that Atlanta has the busiest airport on earth, you're not alone

  • Reports about a major power outage pointed out that Atlanta is home to the world's busiest airport
  • Atlanta's Hartsfield-Jackson airport is home to Delta Air Lines and plays an important role as a connecting hub for the United States

Ask most people to name the location of the world's busiest airport, and you're likely to hear guesses ranging from New York and London to Beijing and Tokyo.

But that title goes to Hartsfield-Jackson International Airport, in Atlanta.

A major power outage sent the air hub into disarray over the weekend, as thousands of passengers were hit with major cancellations and delays. But the news left many people most surprised to learn that Hartsfield-Jackson is the world's busiest.

According to Airports Council International, more than 104 million passengers passed through the airport in 2016, a 2.6 percent increase over 2015. Hartsfield-Jackson has been the world's busiest airport by passenger traffic since 1998.

That means the airport in America's Southeast is busier than counterparts in Beijing, Dubai, Los Angeles and Tokyo— which round up the top five in 2016 by passenger traffic:

Geography ... and Delta

Hartsfield-Jackson plays a critical role as a connecting hub for the larger United States, which is the world's biggest economy.

According to a fact sheet released by Hartsfield-Jackson, Atlanta is within a two-hour flight for 80 percent of the U.S. population.

The airport is a major connection for flights, serving 150 U.S. destinations and more than 75 destinations in 50 countries.

It handles some 2,500 flights and 275,000 passengers a day.

Hartsfield-Jackson airport is home to one of the world's largest carriers, Delta Air Lines, which was founded in Georgia. It began as a crop-dusting company before temporarily moving to Louisiana in 1925.

Last year, Delta renewed its lease agreement for another 20 years.

—CNBC's Leslie Josephs contributed to this story