The St. Agatha and St. Gertrudis Chapel in Fleckenberg is the oldest building in the village still largely preserved in its original state. It was entered in the list of monuments of the town of Schmallenberg on December 10, 1992, not least because of its painting and the preserved furnishings. Some Oberfleckenberg farmers began building this church, which was consecrated on October 10, 1666, probably as early as 1665.