Tenzing-Hillary Airport -- Nepal
Planes headed to Nepal's Tenzing-Hillary Airport, near Mount Everest, land on a runway built a staggering 9,200ft above sea level. And if that wasn't enough to make you reach for the airplane safety card, it's also near a cliff's edge. Unsurprisingly, this one also made our list of the world's scariest runways.
Gisborne Airport -- New Zealand
The only known intersection of a runway with a railway in the world, planes and trains (no automobiles) can get insanely close to each other at Gisborne. To avoid crashes, air traffic controllers turn the lights on the runway red or green, while a ground controller does the same for the trains. Skip ahead to the 2:50 mark of this (unnecessarily long) video to spy a plane landing over the railway.