Punakha Dzongkhag has been inextricably linked with momentous occasions in Bhutanese history. It served as the capital of the country from 1637 to 1907 and the first national assembly was hosted here in 1953. Punakha Dzong is not only the second oldest and second largest dzong but it also has one of the most majestic structures in the country. October 13, 2011 marked an unforgettable wedding of the King of Bhutan, Jigme Khesar Namgyel Wangchuck to Jetsun Pema which was held at Punakha Dzong. Punakha Dzong was built at the confluence of two major rivers in Bhutan, the Pho Chhu and Mo Chhu, which converge in this valley. It is an especially beautiful sight on sunny days with sunlight reflecting off the water onto its white-washed walls. In addition to its structural beauty, Punakha Dzong is notable for containing the preserved remains of Zhabdrung Ngawang Namgyal, the unifier of Bhutan as well as a sacred relic known as the Ranjung Karsapani. This relic is a self-created image of Avalokiteswara that miraculously emerged from the vertebrae of Tsangpa Gyarey, the founder of the Drukpa School when he was cremated. Punakha valley has a pleasant climate with warm winters and hot summers. It is located at an average elevation of 1200 m above sea level. Owing to the favourable climatic conditions, rice has become the main cash crop cultivated in the region.