This bell tower was located on the territory of the Russian Legation (Nanguan) at the former Dongjiangmixiang Alley, renamed West Legation Street after the Yihetuan Uprising of 1900, now Dongjiaominxiang Alley, Dongcheng District, Beijing.
According to "Siege days" by Ada Haven Mateer, this bell tower was a great square building in front of the church.
1898 photo from UK