Dating back to the 10th century, this Chinese-styled mosque is Běijīng's largest and was the burial site for several Islamic clerics. Surrounded by residential high-rises, the temple is pleasantly decorated with plants and flourishes of Arabic. Look out for the main prayer hall (only Muslims can enter), women's quarters and the Building for Observing the Moon (望月楼; Wàngyuèlóu), from where the lunar calendar was calculated. Dress appropriately (no shorts or short skirts).