Mongar Dzong was built in 1930 and its composition was like Lamai Goenpa in Bumthang, the palace of the 1st King Gongsar Ugyen Wangchuck.
They constructed this Dzong in the year as the administrative headquarters for the District and to house the divine monks. The Dzong still houses the relics of the former Zhongar Dzong besides the other monuments. The Mongar festival is held annually in November/December, corresponding to the 8-10th day of the 10th month of the Bhutanese calendar year.
These dates differ from year to year corresponding to the Buddhist calendar. Astrologers complete these determine before the year commences.