Hartenfels Castle takes forever to visit. Plan 3 hours if you want to see all including hanging out at the bear cage. I actually think the castle would be better world heritage than the castle chapel but it is ONLY the chapel within the walls that wants to be inscribed, well noted by the ticket seller here, and it is free to visit. So if you just want to see the chapel it will take you a lot less time.
Martin Luther (maybe you know him for translating the bible but who knows) is credited for how the church looks like, and in fact how ALL evangelist churches should look like. There is a document (not here) that describes this better. If the document would be on display I would like to have this incribed but without and being VERY renovated I am totally against it. There is one corner of the original church that seems to fit the bill but the rest is modern and not worth seeing. I enjoyed the bears sitting around more than the church.