Trongsa Dzong which is the largest Dzong in Bhutan at an altitude of 7,500 feet is a labyrinth of temples, corridors and office holding court over the local community. Protected from invaders by an impenetrable valley, Trongsa Dzong is an impregnable fortress. It is built on many levels into the side of the hill and can be seen from every approach to Trongsa heralding its strength as a defensive stronghold. The Dzong was originally built in 1648 by Shabdrung Ngawang Namgyal, which was later extended by its powerful Penlops, and the sixteenth Desi Sonam Lhundub. Because of its highly strategic position as the only connecting route between east and west, the Trongsa Penlop was able to control the whole of the eastern region effectively. It was the seat of power over central and eastern Bhutan. Trongsa Dzong is the ancestral home of the Royal Family and both the First and Second King of Bhutan ruled the country from this ancient seat. All four Kings held the post of Trongsa Penlop (honorary governor) prior to being crowned as King.
Ta Dzong or watch tower which once guarded Trongsa Dzong from internal rebellion stands impressively and provides visitors an insight into historical significance of Trongsa in Bhutan’s history.