Punakha Dzong was built in the years 1637 to 1638. It was constructed by Zhabdrung Ngawang Namgyal, the founder of Bhutan, and is the second oldest and second largest dzong in the country. The dzong was strategically built at the confluence of the Pho Chhu and Mo Chhu rivers and served as the religious and administrative center of Bhutan until the mid-1950s. It is also known as Pungtang Dechen Phodrang, meaning "The Palace of Great Happiness" or "The Palace of Great Bliss".