This is an interesting structure poised on the hill between Burg Stahleck and St. Peter's church. The path to Werner Kapella is part of the one to walk around the church. You should know that it is fenced off so you can't get really close.
The Kapelle was built around 1290.
This is lit up at night as well as St. Peter's church. If you make your way to the top of the hill across from this you can get a very interesting view of the town.
Be well take care.