There are some 3,800 rectangular courtyards, 387 well preserved, spread out in this small town. These idiosyncratic domestic buildings have more or less retained the slyle of the Ming and Qing dynasties: the outer walls are usually made of grey bricks bound with white lime mortar reaching up to a height of seven or eight yards with no windows but crenellated tops, which gives it an imposing look, iust like a citadel.