Mannheim, Germany- lots of questions

Go to the German Rail query page and put in from "Mannheim Hbf" and to "Mannheim, Wasserturm (Tourismus)". Change the pull-down from Station/stop to POI. Select any Sunday this year (the schedule only goes out until Dec. 13). After clicking on "Search..", click "Details for all". It will show you a 1,1km, 14 min walk with a map at "show". It might also show some streetcar connections (I found streetcars for Sun, 8 Jun, but not for Sun, 15 Jun).

My impression of Mannheim, in the limited amount of time that I passed through, was similar to many smaller cities throughout Europe- very little to distinguish it, but pleasant enough to pass some time. So yes, after a short visit, the remainder your time would be better spent in Heidelburg or exploring the Rhineland.

If you just want to stop in Mannheim to see the water tower and then go on to Heidelberg, you can leave your luggage in a locker at the station. According to an official map I have of the station, the lockers are on the ground floor of the station, directly over the connecting tunnel at the NW end of the tracks (LH end as you look at the bldg from the tracks).

When you return to the station, you can take the S-Bahn to Heidelberg. It looks like the S-Bahns to Heidelberg leave from tracks 9 & 10 (and occasionally 8), far platform away from the station bldg.

Wasserturm is only two tram stations from the train station. You could even walk. Also make sure you visit the completely renovated baroque palace/castle. It DOES look just like Versailles now again (just like it must have looked before the war). I was very impressed. Trams work fairly easy in Mannheim. The castle station is "Schloss", the Wasserturm station is "Wasserturm". Also make sure you visit the Rhine river front on the other side of the castle...

Heather, I would go straight to Heidelberg after you have visited the water tower in Mannheim. There really isn't much in Mannheim to see. You would enjoy Heidelberg more. The castle is stunning and there are several gorgeous churches throughout the downtown area. I would also suggest walking across the bridge over the Neckar River and follow a path up the mountain across from the downtown area. It will give you wonderful views of Heidelberg's downtown with the castle towering over it. Also, if you are into history, there are alot of neat things to see if you continue to climb up the mountain. There is a forum built by the Nazi's, an old Monestary and several other interesting things. The walk is a bit strenuous but there are several benches to sit on along the way. Also, I would suggest the short bus ride to Schwetzigen. It has a gorgeous palace along with the palace garden. Its a very nice little town, its where my husband and I spend most of our time on the weekends.

Thank you so much for all the replies- I really appreciate everyone's input!