St. Marien is the largest of Stralsund's three great Brick Gothic churches and was the church of the patrician merchant class who financed it across the 14th and 15th centuries. The interior is vast — 42 metres to the nave vault — and relatively undecorated, which gives the Brick Gothic structure itself the full attention it deserves.
The Stellwagen organ in the west gallery is the chief treasure. The church also contains a 15th-century astronomical clock (now no longer functioning) and a collection of medieval painted panels. The tower offers a panorama of the old town's roofscape; the view to the west is over the Frankenteich lake, one of the three that bound the island town.