Paro Airport (IATA: PBH, ICAO: VQPR) is the only airport in Bhutan, six kilometres (three miles) away from Paro. The airport is located at a high altitude in a steep valley on the bank of a river, with nearby peaks as high as 5.48 km, and is known as "one of the world's most challenging airports". All flights at Paro are by visual flight rules only and are restricted to daytime hours.
The airport has one runway and is served by a single airline, the national carrier Drukair which has its base there. - Wikipedia