Founded during the height of the Tang dynasty in 742, this is one of the most tranquil places in town and the center of a sizable Muslim community, residents in Xi'an for over 1,200 years. As with Baxian An, half the adventure is getting there, as you veer left just north of the Drum Tower. The covered alleyway, Huajue Xiang, has good-humored vendors selling all manner of weird merchandise and it may take you a few attempts to find the mosque. The courtyards are spacious and have a gardenlike feel, with a wonderful fusion of Arabian and Chinese architectural styles. To the right of the entrance is a hall filled with exquisite Ming furniture. The central courtyard has a triple-eaved octagonal "minaret" from which worshipers were traditionally called to prayer, although it is far more akin to a Chinese pagoda. The prayer hall is normally closed to non-Muslims. As this is an active mosque, be circumspect in taking photographs. Avoid visiting on Friday, when access to the mosque is restricted. Be sure to bring mosquito spray in the summer.