Reichenau Island is an island in Lake Constance in southern Germany. The island is connected to the mainland by a causeway that was completed in 1838.
“The island of Reichenau on Lake Constance preserves the traces of the Benedictine monastery, founded in 724, which exercised remarkable spiritual, intellectual and artistic influence. The churches of St Mary and Marcus, St Peter and St Paul, and St George, mainly built between the 9th and 11th centuries, provide a panorama of early medieval monastic architecture in central Europe. Their wall paintings bear witness to impressive artistic activity.”
The stamp on the right is a matching stamp, it shows also some of the wall paintings.