Heidelberg seems to have it all, a riverside location, lovely old buildings, schnitzel, and even a ruined castle looming over the city and five little Christmas Markets at the end of the year. What's not to like?
Himeji Castle, Hyogo Prefecture, Japan. This is one of the few castles that is an "original." Many Japanese castles were bombed out during WWII and rebuilt afterwards. Himeiji-jo did not suffer that fate and is intact in its original form. It is quite lovely inside and out.