Heidelberg, Germany

Heidelberg, the quintessential German Romantic city, lies 100 km northeast of Strasbourg in Baden-Württemberg, reachable in about 1 hour 20 minutes by IC or RE train (change at Karlsruhe; €20–€40 return via bahn.de). By car, the A5 motorway north from Strasbourg, joining the A656 near Mannheim, delivers visitors to the Heidelberg old town in approximately 1 hour 10 minutes; parking garages near the Kornmarkt are plentiful at roughly €2/hour.

Heidelberg Castle (Schloss Heidelberg), perched 80 metres above the old town on the north face of the Königstuhl, is the defining sight: a vast complex of Renaissance and Baroque ruins with panoramic views over the Neckar river valley and the Odenwald forest. The Bergbahn funicular from Kornmarkt connects the lower old town to the castle in four minutes (€9 return including castle courtyard entry); the uphill path on foot takes about 20 minutes. Inside, the cellars house the Großes Fass — the world's largest wine barrel, holding 220,000 litres — and the Deutsches Apotheken-Museum, an engaging collection of historical medical equipment included with castle admission.

The Altstadt below is Germany's most visited non-federal historic district. The kilometre-long Hauptstrasse pedestrian street connects Bismarckplatz to the Marktplatz, passing the elaborately decorated Haus zum Ritter (1592) and dozens of bookshops and patisseries. The 18th-century Alte Brücke stone bridge across the Neckar leads to the Philosophenweg, a 2 km hillside promenade through orchards and terraced gardens with outstanding castle-and-city panoramas.

Suggested day arc: arrive by 10 h, take bus 33 or walk from Heidelberg Hbf to Kornmarkt (10 min), ride the funicular to the castle (90 minutes for courtyard and Pharmacy Museum), descend through the castle garden on foot, lunch at the Kulturbrauerei brewery restaurant on Leyergasse 6 (€12–€20), then walk Hauptstrasse, cross the Alte Brücke, and ascend the Philosophenweg for late-afternoon views before the return train.