Take Heidelberg’s castle as your starting point: hop on the funicular from the Kornmarkt and save your energy for a descent on foot. Actually, the “castle” is a rambling complex of buildings from various centuries; that most of them are in ruins only adds to the charm. The Apothekenmuseum, with its vials and phials and potions, is an entertaining overview of remedies through the ages.
Back down in the old town, the winding streets encourage exploration, from the heights of the Heiliggeitskirche to the pleasing expanse of the Rathausplatz. A large student population prevents the city from becoming a museum and keeps the taverns busy.
Definitely worth doing this tour. Natalie, our tour guide was very good, funny and informative. Very good getting us right up to the castle and the old part of the city, so age is not a concern on this tour. Did cost me 2 euros to find a WC before the trip back to Frankfurt, so do not drink to much coffee or beer on the trip.
It was a great tour and a lovely way to see some more of Germany outside of Frankfurt.