Stralsund has two main churches. An old one, and a tall one. I think there is a third famous church, but it is now decommissioned and now functions as a cultural center, if I have heard correctly. Anyway, I visited the St. Nicholas Church, which is located just next to the Rathaus. This is the oldest church in town, and is in existence since the 13th century.
The interesting thing about this church is that the entrance is not that obvious. It is very close to other buildings, that the entrance seems to have been rerouted through this one building that faces the square. The church building, on the other hand, does not face the square, and so I had to walk around the church several times to figure out how to enter this place. There is an entrance fee, but it is rather modest.
This church isn't the prettiest, at least from the inside. It started as a Catholic Church, if I understand correctly, and then because of the Reformation, then the idols were removed. Later on, the altars (there are numerous altars inside) and chapels were privatized, so to speak, so some became cemeteries. You can see the stone tablets chronicling the deaths of the people who are buried inside.
I am just including pictures of the dark interior and main altar. I have seen prettier churches than this one, but I still would recommend a visit to this, simply because learning about the church is pretty much learning about the history of the city. You probably won't be awed by this church, but every piece of this building seems to tell a story of its own that is worth listening to.