It was the seat of power over central and eastern Bhutan and the vanguard of the warriours. All the Kings of Bhutan first invest as the Trongsa Penlop before ascending the Raven Crown throne. the massive Trongsa Dzong is the largest fortress in Bhutan which stands on a spur overlooking the gorge of the Mangdi Chuu river. This strategically placed structure is the first sight long before reaching Trongsa. The Dzong is the massive structure with many levels, which slope down the contours of a hill on which it perches. Because of its highly strategic position as the only connecting route between east and west, the Trongsa Penlop was able to control the whole eastern region effectively. It is in this Dzong the annual Trongsa Festival is performed during December or January. The intricacy of its maze of buildings on successive levels is clearly visible from the town. Beyond any doubt its size, design and position make it the most impressive Dzong in Bhutan. It is one of the most aesthetic and magnificent works of traditional Bhutanese architecture.Trongsa Dzong is an important administrative building, providing the headquarters of the Government of Trongsa District. Trongsa provides a strategic central location to control Bhutan and for centuries it was the seat of the Wangchuck dynasty of penlops (governors) who effectively ruled over much of eastern and central Bhutan, and from 1907 have been Kings of Bhutan.