St. Johannis is the main Protestant church of Schweinfurt, a Gothic hall church built in the 14th and 15th centuries that survived the wartime bombing of the city. The interior is spacious and relatively plain — Reformation-period whitewashing removed most of the medieval decoration — but the proportions are good and the Gothic vaulting over the nave is well preserved.
The church interior is open during the day and worth a brief visit on any walk through the old town. The church tower can be climbed for views over the rooftops, though it's not the most dramatic viewpoint in Franconia.