Built in 1648, Trongsa Dzong is a massive structure with many levels, sloping down the contours of the ridge on which it is built; it is the largest Dzong in all of Bhutan. It was the seat of power over central and eastern Bhutan, with both the first and second kings of Bhutan ruling the country from this ancient seat. All four kings were invested here as Trongsa Penlop (“governor”) prior to ascending the throne. Trongsa Dzong is a powerfully built fortress and exemplifies dzong architecture. It is an extensive complex, set on many different levels and includes a maze of courtyards, passageways and corridors leading to as many as 25 temples. The watchtower, a narrow structure with two wings that project in a v-shape from the main part of the building also includes a temple. Called a Ta Dzong, the towers are located above the gorge to the east side of the dzong.