Like Turkmenistan, you can’t just waltz into Bhutan as an independent traveler. Instead, you have work with a travel agent who will create an itinerary and organize your visa, and you’ll have to pay for all of it -- meals, housing, flights, buses -- up front. Via money transfer too, which doesn't make things easier. Plus, Bhutan is one of the more expensive places in the world to visit, so be prepared to spend the government-mandated minimum of $250 a day on taxes, guide, accommodation, and meals.
The best way to access this remote Himalayan kingdom is to fly in from Bangkok, Singapore, Kathmandu, or Delhi, though only a handful of flights operate each week and few planes can land on the short/high (7,300ft above sea level) runway at Paro's International Airport.