Constructed in the 15C, the Qianmen Gate (or Front Gate), marked the border between the old Tartar city and the Chinese city. Formerly defensive in origin and hemmed in by ramparts, it now stands, somewhat superfluously, on manicured lawns to the south of Tiananmen Square. It's possible to climb to the top for a glimpse of the square, as well as the rooftops of the Forbidden City, which is partially obscured by the mausoleum of Chairman Mao.