The Catholic church of St. Michael in Schmallenberg-Holthausen was built by the local community in 1927. It is made of typical regional graywacke and differs significantly from the surrounding churches with its round east tower and unplastered façade.
The construction was necessary because the previous building had become too small. The land was donated by the missionary bishop Franziscus Hennemann from Holthausen. The construction manager was vicar Otto Möbius, who organized the construction with a great deal of voluntary work from the congregation. Over 10,000 hours of voluntary work were put in, including stone quarrying, timber transportation and roof slate work.
The interior features stained glass windows from the 1950s, including scenes of St. Michael the Archangel and the Sermon on the Mount. A carved choir screen from 1985 shows the works of mercy.
A Way of the Cross leads to the nearby Hagen Chapel. The 12 slates from 1858 are easily accessible via Kirchstraße.