The Mangturm is a medieval harbour tower at the western end of the old harbour, built in the 13th century and serving as Lindau's lighthouse until the New Lighthouse was erected in 1856. The tower is capped with a distinctive conical roof decorated in coloured tiles and topped with a weathervane; it has become one of the most recognisable medieval structures on Lake Constance.
The tower is not open to the interior but is easily visible from the harbour promenade. It marks the original medieval harbour entrance, and standing beside it gives a clearer sense of how the harbour has expanded since the 13th century. The coloured tile roof was added in a 19th-century restoration and is more decorative than historical, but it is why the tower photographs so well.