The Hồ dynasty only lasted for seven years (1400-1407), but this period still saw the construction of one of the greatest monuments of the feudal era - the Tây Đô Citadel in Thanh Hóa Province, constructed by Hồ Quý Ly to serve as the nation's capital. What remains of this 900 by 700 metre fortress with its 6 metre-high ramparts is sufficient to illustrate that citadel architecture had by this time reached a very high level of development.