High above the centre, the Romanesque and Gothic St Stephansmünster shelters a faded fresco cycle, Martin Schongauer’s The Last Judgment (1491), and a magnificent altar triptych (1526) carved from linden wood. From the tree-shaded square outside, the Schänzletreppe leads down to Gutgesellentor, the gate where Pope John XXIII was scandalously caught fleeing the Council of Constance in 1415.