Trongsa Dzong is the largest dzong fortress in Bhutan , located in Trongsa ( formerly Tongsa ) in Trongsa district , in the centre of the country . Built on a spur overlooking the gorge of the Mangde River , a temple was first established at the location in 1543 by the Drukpa lama , Ngagi Wangchuk son of Ngawang Chhojey . In 1647 , his great-grandson Shabdrung Ngawang Namgyal ( Shabdrung or Zhabdrung being his title ) , constructed the first dzong to replace it , called Chökhor Rabtentse Dzong with a shorter version of Choetse Dzong . It was enlarged several times during the 18th century ; the Chenrezig Lhakang was built in 1715 and a whole complex , including the Maitreya ( Jampa ) temple , was added in 1771 . The dzong has since been repaired on several occasions ; it was damaged during the 1897 Assam earthquake and underwent extensive renovation in 1927 and 1999
1897 Assam earthquake
1897 Assam earthquake
Trongsa Dzong