Dzong architecture is used for dzongs, a distinctive type of fortified monastery (, , ) architecture found mainly in Bhutan and Tibet. The architecture is massive in style with towering exterior walls surrounding a complex of courtyards, temples, administrative offices, and monks' accommodation. Characteristics Distinctive features include: High inward sloping walls of brick and stone painted white with few or no windows in the lower sections of the wall Use of a surrounding red ochre stripe near the top of the walls, sometimes punctuated by large gold circles Use of unique style flared roofs atop interior temples Massive entry doors made of wood and iron Interior courtyards and temples brightly colored in Buddhist-themed art motifs such as the ashtamangala or swastika Regional differences Bhutan Dzongs serve as the religious, military, administrative, and social centers of their district. They are often the site of an annual tsechu or religious festival. The rooms inside the dzong are typically allocated half to administrative function (such as the office of the penlop or governor), and half to religious function, primarily the temple and housing for monks. This division between administrative and religious functions reflects the idealized duality of power between the religious and administrative branches of government. Tibet Tibet used to be divided into 53 prefecture districts also called dzongs. There were two dzongpöns for each dzong, a lama and a layman. They were entrusted with both civil and military powers and are equal in all respects, though subordinate to the generals and the Chinese amban in military matters, until the expulsion of the ambans following the Xinhai Revolution in 1912. Today, 71 counties in the Tibet Autonomous Region are called dzongs in the Tibetic languages. Siting of dzongs Bhutanese dzong architecture reached its zenith in the 17th century under the leadership of Ngawang Namgyal, the 1st Zhabdrung Rinpoche. The Zhabdrung relied on visions and omens to site each of the dzongs. Modern military strategists would observe that the dzongs are well-sited with regard to their function as defensive fortresses. Wangdue Phodrang dzong, for instance, is set upon a spur overlooking the confluence of the Sankosh (Puna Tsang) and Tang Rivers, thus blocking any attacks by southern invaders who attempted to use a river route to bypass the trackless slopes of the middle Himalayas in attacking central Bhutan. Drukgyel Dzong at the head of the Paro valley guards the traditional Tibetan invasion path over