The Franciscan church just south of the Main Square is one of Krakow's oldest ecclesiastical buildings — founded in the 13th century and rebuilt repeatedly since. The church is important enough historically, but what makes it unmissable are the extraordinary Art Nouveau interior decorations created by Stanisław Wyspiański at the turn of the 20th century.
Wyspiański, the painter, playwright, and designer who was the central figure of the Polish Young Poland movement, designed the stained-glass windows and the entire decorative scheme of the nave between 1895 and 1904. The result is a complete Art Nouveau environment — floral murals cover every wall surface, the windows glow with symbolic imagery, and the main apse window shows Wyspiański's famous interpretation of God the Father. It is one of the most complete and distinctive Art Nouveau church interiors in Europe. Entry is free; the church is an active place of worship, so visit respectfully and avoid peak mass times.