There are two options in entering the Bhutan it’s either by land or by flights as Bhutan is a landlocked country so there is no provision of entering the country by seaways.
The Paro Airport is Bhutan’s only air field and many consider it to be one of the most beautiful in the world. The airport offers the flights to destination like Bangkok, Delhi, Kolkata, Bagdogra, BodhGaya, Dhaka, Kathmandu, Guwahati, Singapore and Mumbai. There are also domestic airports in Yonphula in eastern Bhutan, Bumthang in central Bhutan, and Gelephu in south-central Bhutan.
The flight between Paro and Kathmandu is one of the most exciting ones as the aircraft passes over four of the five highest mountains in the world. In fine weather you can enjoy the spectacular view of Mt. Everest, Lhotse, Makalu and Kanchenjunga at their best.
If your are planning to enter Bhutan by overland then Phuentsholing, Gelephu and Samdrup Jongkhar ar the only land borders areas open to tourists. You can either enter from Phuentsholing while coming from the west, Gelephu is the entry point if you are travelling from the ventral region and Samdrup Jongkhar is the only option to enter the Dragon Country from the east.