Meet your guide at the Rathaus in Marktplatz and begin your journey through Heidelberg. Start at the square, which has been the city's stage for 500 years. Learn what happened on these stones long before the cafes arrived.

Next, visit the Heiliggeistkirche, a church that was divided by a wall down the middle to accommodate two faiths. Continue to the Hotel Zum Ritter St. Georg and learn why this hotel carries so much history. Then, take a slow walk down Hauptstrasse, Europe's longest pedestrian street, and discover the doorways and side alleys most people rush past.

Stop at the Studentenkarzer and University Museum, Germany's oldest university, founded in 1386, and the jail where students were proud to be locked up. Walk through the museum's different sections. Then, visit the Jesuitenkirche, a Baroque interior most visitors never step into, and learn why it was built here and who it was really meant to convince.

Next, visit the Old Bridge (Karl-Theodor-Brücke) and learn why every Heidelberg photograph starts here. Then, see the Brückenaffe, the bridge monkey, and learn why the monkey holds a mirror and what it was actually warning people about.

Continue to the Zwingerstraße fraternity houses and discover the world of the old student societies, hidden in plain sight, plus a few other tucked-away places along the way. Then, visit the Kornmarkt and the funicular and get practical recommendations for getting up to the castle, what is worth your time inside, and what to skip.

Finish your tour at Karlsplatz and take in a few small spots in this corner of the old town.