The Herzogenburg Abbey is a Roman Catholic monastery of the Augustinian canons.
The monastery was founded in 1112 by Ulrich I von Passau in St. Georgen an der Traisen at the confluence of the Traisen and the Danube and was moved 10 km up the Traisen to Herzogenburg in 1244 because of the frequent flooding. This also gave rise to the "Upper Market", which was managed by the Canons' Convent, while the "Lower Market", a Bavarian foundation, remained in the hands of the Formbach Monastery until it was bought by the Canons' Convent in 1806.
The largest renovation of the monastery since the conversion took place with enormous support from tax money from the state of Lower Austria and the city of Herzogenburg and private donations from the year 2000 and was completed for the 900th anniversary in 2012. The entire exterior façade and parts of the inner courtyards were restored. The historic gardens, such as the prelate's garden, the orchard and the rose garden were also revitalized. Much has also been renovated inside, such as the ballroom, the Frigdiani and choir chapels and the monastery library including its book inventory. Excluded from the renovation, however, were the church itself and the magnificent baroque tower of the collegiate church, the architectural counterpart to the Dürnstein collegiate tower and landmark of the lower Traisental.