By Flight - Paro International Airport/Bhutan is connected directly to Nepal(Kathmandu), India(NewDelhi, Kolkata, Bagdogra, Guwahati, and Gaya), Bangladesh(Dhaka), Thailand(Bangkok)and Singapore(Changi). At present two carriers operate to Bhutan, Drukair and Bhutan Airlines. We took flight from Bagdogra to Paro (1 hrs).
When you learn how difficult it is to land on such a challenging and beautiful airport. Kudos to the Pilots.