Formidable-looking Simtokha Dzong stands on a hillside at the southern end of Thimphu Valley, astride the old road to the Dochula Pass and eastern Bhutan beyond. Built in 1629 by Bhutan's great unifier, Zhabdrung Ngawang Namgyal, allegedly to stop a local demon that was harassing travelers, the fortress was the first dzong to house civil and religious functions in a single structure and became a prototype for dzongs across Bhutan.
The original structure was occupied by Tibetan invaders in 1630, but the Zhabdrung regained control when a fire killed the interlopers. The dzong has been restored and enlarged many times in the centuries since, and today it consists of a three-story utse encircled by prayer wheels and beautiful slate carvings. At the heart of the main lhakhang sits a statue of Shakyamuni, surrounded by intricate murals, some of the finest of their kind.