Church-building on Reichenau Island was not limited to the monastery church. In the 9th century, around 888, Abbot Hatto had the church devoted to Saint George erected in Reichenau-Oberzell. The nave, with its Ottonian mural paintings (the only ones preserved from the time before 1000 north of the Alps) can still be admired today. They were probable painted in the period between 900 and 1000 and show the miracles of Christ.
Visitors enter the church is entered through the porch and reach a nave with a flat painted wooden ceiling. Connected to this are low aisles, a square crossing area and the rectangular chancel four steps higher. Above the entrance to the crypt lies a tomb in which the relics of George are kept. In addition to the nave, mural paintings can also be found in other parts of the building, however these are of a more recent origin.
The church of St. Peter and Paul in Reichenau-Niederzell was built in the 12th century at the site of a previous church consecrated in 799. Its East towers are from the 15th century, and a western porch was built in the 16th or 17th century. After the older church had been torn down, this three-nave basilica was erected. In the semi-circular apse a painting from the 12th century, depicting Christ in the mandorla and the apostles, can be seen.
Over the course of the centuries additional decorations were added to the church, and today it offers numerous other mural paintings in the southern side chapel (scenes from the Passion), on the northern aisle, in the chancel (scenes with Peter) and in the porch (scenes from the Passion). In 1756-57 St. Peter and Paul was converted to the Baroque style. Flat ceilings adorned with Rococo stuccowork were installed. Today this Baroque phase is still clearly apparent in the Romanesque church.