Simtokha Dzong :

Five miles from Thimphu, on a lofty ridge, stands Simtokha Dzong the oldest fortress in the Kingdom. Simtokha's strategic position overlooks the entire Thimphu Valley. The central tower has 12 sides, unlike any other Fortress in Bhutan. It also contains the bed chambers of Zhabdrung Ngawang Namgyel and Jigme Namgyel, the father of first king of Bhutan