Planning for next year October-traveling from Cochem on to Lucerne and thought we would stop in Heidleberg. Looking for suggestions other than the castle for site seeing as well as a recommended hotel and good restaurant. Probably be there 1.5 days.
A few recommendations. On the opposite side of the river from the castle, on top of the Heiligenberg, there's the ruins of a medieval monastery and a completely intact Nazi-era ampitheater (one of the largest remaining building projects from the period). A trip, either by boat, car or commuter train up the Neckar River is worthwhile. There's several castles and a number of attractive towns. It isn't in the same class as the Rhine valley, but it compares well to the Mosel. Finally, the nearby town of Schwetzingen hosts a large baroque palace complete with formal gardens. I've only spent the night once in Heidelberg, and I stayed at the Hotel Hollander Hof. The location is right next to Karl-Theodor Bridge.
My favorite restaurant was Hackteufel on Steingasse near the old bridge (also a hotel). Very good traditional German fare. I also really enjoyed the restaurant of the Hollander Hof, but it might be closed now.
We were just in Heidelberg last month. We had just arrived from the US and wanted some place to get over our jet lag for a couple of days. We stayed at the Crown Plaza City Center primarily because we took the shuttle to Heidelberg and the hotel is the pick up/drop off point. But we really enjoyed our stay. I booked an advance purchase non refundable rate of 124 Euro. The hotel is just a short walk to the Castle and all the shops and restaurants in the old town.