Cliffs on three sides.
Christopher J. Fynn — CC BY-SA 3.0 · Christopher J. Fynn — CC BY 3.0 · Franzfoto — CC BY-SA 3.0 · Christopher J. Fynn — CC BY 3.0
Trashigang Dzong, the «Fortress of the Auspicious Hill», is one of Bhutan's largest dzongs, standing on a rocky ledge in the east. It lies far off most visitors' routes, so only those who choose to see the country's least visited side reach it. With white walls and yellow roofs above a deep valley, it is among the finest sights in eastern Bhutan. It was built in 1659 to resist invasions from Tibet, on a ledge with steep cliffs on three sides above the Drangme and Gamri rivers. Ngawang Namgyal is said to have prophesied it and tasked the governor of Trongsa, Chhogyal Minjur Tempa, with the work. It housed a monastic community and the district administration, which have moved because of ongoing restoration, according to Wikipedia. You see the building from the road above a dry brown hill, with white walls, golden-coloured roofs and carved timber. Photographs show a courtyard inside surrounded by painted galleries, where religious festivals are held. The fortress looks over two deep valleys and feels very different from the busier valleys of the west. It is about 83 km in a straight line from Jakar, but the road is long: sources give about 198 km from Jakar to Mongar in 7 hours, then about 90 km in 3 to 4 hours. Entry may not be possible because of restoration, so ask your guide. Foreign visitors also pay a Sustainable Development Fee of about 100 US dollars a night, and entry is usually arranged through a company with a licensed guide.
Cliffs on three sides.
Colour over white walls.
A deep view around the dzong.
Above the Drangme and Gamri rivers, Trashigang, eastern Bhutan
Wikipedia mentions restoration, so entry may not be possible, so ask your guide.
Yes. Reaching it from Jakar takes about 10 hours on the mountain road.