The former collegiate church of St. Lubentius in the Limburg district of Dietkirchen on the west bank of the Lahn was the most important church in the Lahngau and its successor territories until the 13th century. In the sacred building the bones of St. Lubentius are kept as relics. The monastery, which dates back to the 9th century, became extinct in the course of secularization. Today St. Lubentius serves as the Catholic and the Trinity Chapel as the Protestant parish church of Dietkirchen.
The building is a Romanesque basilica with a transept and double tower facade, which was essentially given its present appearance in the 11th and 12th centuries. Its unusually monumental external effect results from the interplay of the exposed location on a jagged limestone cliff, the heaviness of the architecture typical of the construction period and the (ahistorical) lack of plastering. The furnishings mainly consist of works from the 18th century.