Punakha dzong was constructed in 1648 by Shabdrung Nawang Namgyel, the Bhutan's unifier. Till 1955, it served as winter capital of Bhutan and even today, it keeps its ritual significance as a venue of royal wedding of fifth king. It also remains winter residence of Je Khenpo, the highest lama of f Drukpa Kagjü branch of Tibetan Buddhism, the state school of Bhutan. It is venue of Punakha Drubchen and Punakha Tshechu festivals, usually held at the end of February or beginning of March.