The former monastery church of the Ottmarsheim monastery (Benedictine nuns), most of which dates from the first half of the 11th century, is one of the most important architectural monuments of the Romanesque period. Its central building in the form of an octagon is modelled on Aachen Cathedral.
In 1030 Rudolf von Altenburg donated a Benedictine monastery in Ottmarsheim, which was to become his burial site. Pope Leo IX (from Eguisheim) consecrated the new church in 1049. The Neuchâtel family devastated the monastery in 1273, the Baslers in 1445 and 1446, the Bernese in 1468. As a result and due to the obligation of royal travellers to stay on the Heerstrasse, the monastery became impoverished. The church and above all the monastery buildings were rebuilt again and again. In 1790 the monastery was secularised and demolished. The church was purchased by the congregation and is still owned by them today.
The octagonal interior under the dome looks very simple.
Two-storey arcades open to the centre of the room, below through low arcades, above through high arch openings with double column arrangement. The light comes in through the galleries. The windows under the dome illuminate only the upper part of the room.
Capitals and bases of the columns are the only decorative elements of the room.
The side aisles are covered with vaults. The choir has a groin vault.
The annexes date from later times, the small chapel in the southeast from the 2nd half of the 15th century. The large chapel in the northeast was built in 1582. It has ribbed vaults with keystones, one of which has the monastery coat of arms.
Photographing the ceiling fresco in the side chapel.