Nepal can be enter by two ways:
By air: Some of the major international airlines operating schedule services to Nepal are Royal Nepal Airlines, British Airways, Biman Bangladesh, China South West Airlines, Druk Air, Gulf Air, India Air, Thai Airways, Qatar, Pakistan Air, Jet Air and Singapore Airlines. By air, you will arrive at the Tribhuvan International Airport (only one international airport) located in the heart of Kathmandu City.
By Road: There are several entry points by land route mainly from Nepal / Indian borders;
Scheduled public as well as tourist buses run to and from Kathmandu. Traveling by bus is recommended if you can cope with 10 to 12 hours of long drive in return for a fascinating mountainous views and snail tail roads that meet above the clouds.