Is AMS (Schiphol) Polderbaan the runway furthest away?
One possible contender is Pyongyang airport. The far end of the new runway (01/19) is around 7 km away from the terminal (as the crow flies). With taxi distance, it is almost 8 km:



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While the taxi times at Amsterdam can be very long, it is a bit misleading to blame it on the runway being 7 km away. Runway 18R is not used for takeoff. Unlike Pyongyang, there is no parallel taxiway on that 'end' of the runway, and Schiphol ATC would never want to wait for an aircraft to backtrack. Hence, it would be more sensible to use the distance from the first taxiway for landing aircraft on 18R, located 5.5 km from the tower.