The squat outside appearance of the church gives no clue to its actual size: 480m long, with 80m towers. Inside, the visitor is struck by the luminosity and varied colours of the frescoes. The solid, amply proportioned transept crossing is surmounted by a flattened dome of grandiose design. In the chancel, the walnut choir stalls (1764) and the organ (1766) form a single ensemble.