A tibetan-style chorten and prayer flags mark the pass at Pele La (3420m), a pass in the Black Mountains that is largely considered the boundary between western and central Bhutan. East of the pass the road leads to Trongsa, site of Bhutan’s largest Dzong and ancestral home of the royal family. Beyond lie the breathtakingly beautiful Bumthang valleys, the heart of Bhutan, a treasury of temples and monasteries, a living museum of art and history.