St Stephen Walbrook

St Stephen Walbrook's medieval predecessor burned in the Great Fire of 1666, and Wren's replacement, built between 1672 and 1679, is where he first worked out in built form the dome he would later scale up for St Paul's. Inside a plain rectangular parish-church box, barely visible from the street because later buildings crowd around it on every side, eight arches rise from twelve free-standing Corinthian columns to carry a coffered dome lit by a lantern, turning what looks from outside like just another City church into a fully domed centralised space. As the parish next to the Mansion House, built decades later, it became the Lord Mayor of London's official church. In 1953 its rector, Chad Varah, founded the Samaritans, the telephone helpline for the suicidal and despairing, in the crypt below, before the charity outgrew the space and moved elsewhere. In 1987 a smooth stone altar by the sculptor Henry Moore was installed directly under the dome, a placement so unorthodox for an English parish church that the Court of Ecclesiastical Causes Reserved had to approve it.