Fraueninsel is 600 by 300 meters in size and has around 300 residents. During ground radar measurements, geophysicists came across previously unknown foundation walls of a Romanesque central building.
The building is located at the highest point on the island and has a diameter of 19 meters. It is unclear whether it could be the grave of Blessed Irmengard, who worked as abbess of the Frauenwörth convent in the 9th century. She was buried in the abbey church in 866 and her grave was opened between 1001 and 1020.