Beijing Dongsi Mosque is the oldest mosque in Beijing. It is located at No.13, the Dongsi South Street, Dongcheng District. The Dongsi Mosque includes two gates while the entrance gate faces east, a minaret, a prayer hall and so on. The prayer hall can accommodate 500 people and Koran is carved on the hall's arches. It is the headquarters of the Beijing branch of the China Islamic Association. Many precious cultural relics are preserved in Beijing Dongsi Mosque.