Heidelberg has to be approached by the river to understand why the Romantic poets made it their favourite city. The Neckar flows between two wooded slopes, rounds one last bend, and suddenly it's all there: the old pink sandstone bridge, the historic town pressed tightly between the water and the hill, and above it, half in ruins yet still commanding, the silhouette of the castle. River ships generally stop at Mannheim or Speyer, about thirty minutes' drive away; some excursion boats travel up the Neckar as far as the foot of the town walls. Either way, the day begins by the water.

The Castle Above the Rooftops

A funicular departs from the Kornmarkt and carries passengers up to the upper terraces in just a few minutes, sparing them a steep climb. Up there, the red sandstone Renaissance façades, torn open by the wars of the 17th century and never fully rebuilt, make up Germany's most famous ruin. In the cellars sleeps the Great Barrel, a cask holding more than 200,000 litres that a legendary court dwarf, Perkeo, is said to have been tasked with guarding, and drinking from; a dance floor built right on top of its lid gives a real sense of its size. From the gardens, the view drops down over the old rooftops and the river, a panorama that travelled the world in engravings long before photography existed.

Germany's Oldest University

Coming back down, the old town's maze of streets unfolds along the Hauptstrasse, a pedestrian street a kilometre and a half long. Heidelberg is home to Germany's oldest university, founded in 1386, and it shows: bookshops, student cafés, baroque façades housing lecture halls and libraries. Also worth noting is the Hotel Ritter, a Renaissance masterpiece from 1592, one of the few buildings to survive the wars of the Palatinate unscathed. One curiosity shouldn't be missed: the student jail, where the university once locked up its more unruly students. Its walls are covered in graffiti and silhouettes left by prisoners, rather proud of their fate, between 1780 and 1914.

The Old Bridge and Its Monkey

The market square, dominated by the Church of the Holy Spirit, leads naturally to the Alte Brücke, the old bridge built in 1788. At its entrance, a bronze monkey holds up a mirror to passersby, a playful nod to human vanity, which visitors touch to ensure they'll return one day. From the middle of the bridge, the view of the fortified heights and wooded slopes alone is worth the trip.

The Philosophers' Walk

On the opposite bank, a gently sloping path, named for the scholars who once came here to think, winds between vineyards and gardens up to a lookout point. This is the best spot from which to photograph Heidelberg: the bridge in the foreground, the rooftops clustered behind it, the royal ruin set against its backdrop of forest. The climb takes a good twenty minutes via the Schlangenweg, the "snake path" that zigzags between stone walls; the benches along the Philosophenweg rank among the best-placed in Europe, and the almond trees that bloom there early each spring are proof of the region's remarkably mild climate.

The Stop in Practice

What the Romantics Got Right

Goethe, Hölderlin, and Turner each tried to capture this landscape; none of them ever exhausted the subject. Heidelberg holds that rare mix of scholarly gravity and easy living, of wounded stone and terraced vineyards. Heading back toward the ship, visitors carry with them the image of the castle glowing in the evening light, exactly the one that, for two centuries now, has convinced travellers to return.