Below the castle Veste Oberhaus sits the Niedernburg Abbey, an 8th-century abbey that was rebuilt following a fire in the 19th century. Though the abbey is now home to a school, the abbey church contains the remains of Gisela, emperor Heinrich II?s sister and widow of Hungary?s first king, Stephan.
On the southern side of the Inn, the Mariahilfberg is the location of a 17th-century monastery pilgrimage church, located in the Innstadt, or Inn City. Here in 1974 archaeologists found the remains of the Roman citadel of Boiotro, a strong fortress that includes walls that are 12 feet thick, and five defense towers. Close by, the Roemermuseum Kastell Boiotro contains relics from the site, including pottery, lead figures, wood carvings, and antique scripts.
