St. Mary's Church, a Romanesque three-aisled pillar basilica with Early Gothic chancel and western tower, was erected in Deutsch-Altenburg in 1050. It was elevated to the status of imperial priory of the Hungarian Marches in 1051 and given as a gift to the imperial widow Agnes in 1058.
Alban and Johann Dörr modified and added to the church in 1213. From the outside, it has one of the loveliest chancels in Austria.