My city Jena
It is the remnant of a castle from around 1000 years ago. The castle is located in the north of village Kunitz and very close to Jena.
From Jena Zwätzen tram stop it is very easy to hike there (around 40 minutes uphill), and from different points on the way, there are very beautiful view points were you can see the whole city.
Visiting Kunitzburg for seeing the sunset is recommended.