Ostönnen (incl. Höberg and Ostönner Linde) is a rural loose cluster village with about 1,100 inhabitants. The Hellweg, the "Alte Heerstraße", determines the historical village center. It is framed by old farm buildings and quarry stone walls. By today's standards, an impressive number of farms keep dairy cattle, making Ostönnen the dairy village of the Soest Börde. In the center of the old part of the village is the St. Andrew's Church, first mentioned in a document in 1169. It is considered one of the most important Romanesque architectural monuments in Westphalia to have been preserved in its original style: a cross-vaulted pillar basilica with apse, choir square and west tower. Inside you can find the oldest playable organ in the world. To the north, at the corner of Schloot and Lindweg, Ostönner Bach and Schlenke join to form Mühlenbach. Here a flood marker reminds of the flood disaster of 1968.