Meet Air Koryo, the only airline in the world that has earned one star from Skytrax, an airline reviewer.
Business Insider reports that this North Korean, state-owned airline has less than 24 Russian-made airplanes that fly to locations such as China, Russia, Switzerland, Bulgaria, Hungary and the Czech Republic.
And the site lets photographs taken by  Mark Fahey, an Australian scientist, showcase just what makes it the worst:
Check out the rest of Business Insider's compilation here.