Heidelberg, Alsace & Black Forest Railway
A Germany-France border rail loop connecting Heidelberg, Baden-Baden, Strasbourg, Colmar, and Freiburg.
Head south from Frankfurt, cross the Upper Rhine Valley into Alsace, France, then return to the Black Forest, and finally head back from Freiburg. Primarily by train, this route features historic towns, thermal baths, and wine villages, with frequent hotel changes. Perfect for first-time travelers who want to experience both the German and French sides in one vacation. The trade-off is skipping the Black Forest High Road, which would require a separate car rental.
Christmas markets are held in December but accommodation is tight; the grape harvest season in Alsace is in autumn.
Day by day
Day 1 · Half-Day in Frankfurt Old Town
Frankfurt（Römerberg & New Old Town、Frankfurt Cathedral、Main Tower）
Take the S-Bahn from the airport to the city center (approx. 15 mins). Walk around the Old Town in the afternoon and climb the Main Tower for the skyline view.
Stay: Old Town and City Center
Day 2 · Head South to Heidelberg for the Castle
Heidelberg（Heidelberg Castle、Old Bridge (Karl Theodor Bridge)、Philosophers' Walk）
Train from Frankfurt to Heidelberg takes about 1 hour. Walk around the Old Town, take the funicular up to the castle, and cross the Old Bridge in the evening.
Stay: Heidelberg Old Town
Day 3 · University Town to Spa Town
Heidelberg（Heidelberg University & Student Prison、Church of the Holy Spirit & Marktplatz） → Baden-Baden（Friedrichsbad、Lichtentaler Allee）
Explore the Old Town in the morning, then take a train to Baden-Baden in the afternoon (approx. 1 hour 15 mins), and take a bus from the station into town.
Friedrichsbad has a nude bathing policy; if you are not comfortable with this, choose Caracalla Spa instead.
Stay: Old Town and Spa District
Day 4 · Cross the Rhine to Strasbourg
Baden-Baden（Mount Merkur & Merkur Funicular） → Strasbourg & Colmar (Alsace)（Strasbourg Cathedral、La Petite France、Barrage Vauban & Ponts Couverts）
Go up Mount Merkur in the morning, and take a train in the afternoon via Offenburg and Kehl to Strasbourg (approx. 1 hour 15 mins).
Stay: Grande Île
Day 5 · Boat Cruise then Transfer to Colmar
Strasbourg & Colmar (Alsace)（Batorama Boat Tour、Colmar Old Town & Unterlinden Museum、Petite Venise, Colmar）
Take an Ill River cruise in the morning (approx. 1 hour), then take the TER to Colmar in the afternoon (approx. 30 mins), and walk from the station into the Old Town.
Stay: Colmar Old Town
Day 6 · Alsace Wine Villages
Strasbourg & Colmar (Alsace)（Riquewihr、Kaysersberg）
Take a bus from Colmar to Riquewihr and Kaysersberg (approx. 30–45 mins one way), returning on the same day.
Buses between villages are infrequent, and even fewer run on Sundays; you can book a half-day chartered tour instead.
Stay: Colmar Old Town
Day 7 · Return to Freiburg, Germany
Freiburg & Southern Black Forest（Freiburg Minster、Freiburg Bächle、Schlossberg Freiburg）
Take a bus from Colmar to Breisach and transfer to a train to Freiburg, or transfer via Mulhouse (approx. 2 hours).
Stay: Freiburg Old Town
Day 8 · Half-Day at Lake Titisee and Return
Freiburg & Southern Black Forest（Titisee）
Train from Freiburg to Lake Titisee takes about 40 mins; return in the afternoon and take the ICE to Frankfurt Airport (approx. 2 hours).
It is safer to schedule your flight in the evening; you can skip Lake Titisee if time is tight.