dirang dzong located on top of a hill was built in 17th century.  it has a historic importance. during vietnam war it was used as jail and in world war time, it was used as shelter. the dzong area is a tribal area and has old houses which were made in such a way to protect the people from cold weather. some of these houses are over 500 years old. the entry is through a stone staircase which provides excellent view of surrounding area.