Our plane descended between the 18,000-foot peaks of the Himalayas into the narrow, temple-dotted valley of Paro, Bhutan. It’s a very technical airport landing, in a country with extremely tight tourism policies, but no one said it was easy to reach Shangri-La. This tiny Buddhist kingdom, landlocked between India and China, only got roads to the outside world in 1962 and opened to travellers less than 50 years ago. By