The west façade of this church is built out of red sandstone from the Vosges. The porch comprises a central rib vault between two barrel vaults. The narthex, which is crowned with domes, is the only Romanesque part of the interior. In the arms of the transept there are funerary monuments, which were erected in 1621 and badly damaged during the Revolution, and you will also see superb Louis IX stalls in the choir. The authentic Silbermann organ (1710) is among the finest in Alsace. The remains of a pre-Carolingian church were discovered beneath the transept (entry via the crypt).