Druk Air, the national carrier of Bhutan, flies every Monday and Thursday between Kathmandu and the capital Paro. Druk Air also operates connections to Kolkata, Delhi, Dhaka in Bangladesh and Bangkok. You can also enter Bhutan by land, stopping en route in Sikkim and Darjeeling (India). However, visitors must book their trip through one of the 80 tour operators registered in Bhutan, either directly or by contacting their counterparts abroad. The minimum daily rate is set by the Bhutanese Ministry of Tourism and is not negotiable. (These rates may be higher depending on the nature of the services provided.) The rate is the same for cultural tours and treks. Photography in some monasteries and dungs is not permitted. Do not take professional cameras with you as filming is prohibited in Bhutan unless specifically authorized in advance.