Seat of the largest and biggest population of Bhutan, the town of Trashigang lies on a narrow relief between Dangme Chhu and Metri Dang Chhu. Trashigang was in the past a busy center for trade route to Tibet, and today it is an important junction on the east-west highway connecting to southeast region of Samdrup Jongkhar and the Indian States of Assam. Northeast of Trashigang is also home to unique semi-nomadic people of Merak and Sakteng. They have their own custom including unique costumes.
Perched on a narrow ledge facing the northeast frontier, towards Tibet, stands Trashigang Dzong, built in 1659.Its location proved crucial in defending against many Tibetan invaders who tried several surprise attacks. They were exasperated since they did not expect such a high rising fortress in the lowlands of the Himalaya. Tibetan are remembered to have cried in agony, "it is not a dzong on the ground, it is in the sky", and on being tormented by thorny spikes of lemon grass seeds and biting insects believed that the plants and animals were also in support of the Drukpas, the Bhutanese.
24 km from Trashigang, the temple of Gom Kora is set on a small alluvial ground carved by the Dangme Chhu. Surrounded by steep slopes and semi-arid vegetation, it is an oasis of rice fields and plantains. It is one of many places in east visited by Guru Rimpoche. There are rocks in the temple compound and immediate vicinity, which carries foot and body imprint of the Master. A very popular annual festival attracts people from as far as the tribal communities of northeast Indian state of Arunachal.