What is a highland airport?

  Highland airports are divided into two categories: general highland airports and highland airports.  General highland airports: Airports at an altitude of 1,500 meters (4,922 feet) and above, but below 2,438 meters (8,000 feet).  High plateau airports: airports at an altitude of 2438 meters and above.  Currently (until 2014) Sichuan Taocheng Yading Airport is the highest civilian airport in the world at 4,411 meters above sea level.