The Landscape on which the Dzong stands is not only picturesque but arouses curiosity. The hillock like Mount Meru is the site of the palace of the Druk Chhoglay Namgyal (victory of Bhutanese Over enemies in all directions). Trashigang Dzong overlooks the Dangme chhu which flows at its base. It is accessible only from the north, through a slender road, paved by blasting the cliff. Due to its location Trashigang Dzong is one of the most strategically placed Dzongs in Bhutan.
The Dzong was founded according to the prophecies of Zhabdrung Ngawang Namgyal in order to consolidate indomitable power and unparallel reign over the whole of the eastern regions.
In Chhogyal Minjur Tempa ordered the Kudung Pekar Chhophel to build the Dzong at Bengkhar due to its strategic location. In 1659 the Dzong was constructed and named Trashigang Dzong-fortress on the auspicious hill. Around the main Dzong, Dzongchungs (mini-Dzongs) were built, in four cardinal directions. The Dzongchungs unfortunately do not exist today.
During the time of the fourth Deb, Tenzin Rabgye, the entire Trashigang Dzong was enlarged and a Goenkhang was added. In 1710, the second Dzongpon, Khamsum Wangdi, commissioned the writing of the Kanjur (108 volumes of the Buddhist teachings). The present Dzong was enlarged by Dzongpon Dopola, also known as the Trashigangpa, in 1936. He also built an enormous statue of Guru Rinpoche and a Lhakhang dedicated to it.
After its construction Trashigang Dzong withstood various invasions from Tibetan troops. An interesting local saying states that when the Tibetan troops descended from the Muktangkhar mountains on the other side of the Dzong they saw the Dzong below and said “Trashigang Dzong is not a sky Dzong but a ground Dzong”, but when reaching the bank of Dangmechu they looked up and seeing the impenetrable Dzong aloft they agreed that it is really a “sky Dzong” after all and fled.