The St. Marienkirche in Bad Segeberg is one of the most significant Romanesque buildings in Northern Germany. The three-nave brick basilica, whose official documentation dates back to 1199, offers its simple beauty to create the ideal surroundings for the choir and chamber music of the Schleswig-Hostein Musik Festival. The organ, which was built by Marcussen (1873) and then rebuilt by Kemper in 1937 and 1959, is used for the finest concerts. Further areas of interest are the magnificent carved altar, which was built in 1515, and the bronze baptismal font from 1447.