The impregnable Tashigang Dzong is located near the town, and stands on a spur overlooking the Gamri-chhu river 400m below. It was built in 1659 at the behest of Minjur Tenpa, Bhutan's third Desi. In earlier centuries there had been a castle on this hilltop promontory built by local chieftain. 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. During the time of the fourth Deb, Tenzin Rabgye, the entire Trashigang Dzong was enlarged and a Goenkhang was added in 1680s.In 1936, Dzongpon Dopola added a shrine and large statue of Guru Rinpoche. The Dzong was repaired several times over the years.