The 'Old Church' of Diekirch with its two naves in Gothic style, dates back to 1467. In the Merovingian period (6th and 7th centuries), a pre-Romanesque church was built in the place of a Gallo-Roman sanctuary, certain parts of whose walls are still visible today. In the 11th century, this building was replaced by a Romanesque church, whose tour has been kept (12th century). Inside, the church has fine frescoes dating from the 16th and 17th centuries. In 1960, a cemetery, probably from the Merovingian period, was discovered underneath the church.
References:The first written record of church in Danmark locality date back to the year 1291. Close to the church are several stones with a Christian text and cross inscribed. The oldest parts of the present red-brick church are from the 1300s. In the late 1400s the church was enlarged to the appearance it has today. The church has been modified both internally and externally several times, among other things after the fires in 1699 and 1889. There are lot of well-preserved mural paintings in the walls.