Our guide at the Institute of Geog-Paleoentology, removes black velvet padding, to reveal the 610,000 year old jaw of Heidelberg Man. It survived well the millennia, but lost two teeth during the Second World War. A healed fracture scar tells us that in life it was once nursed through weeks of incapacity. Animals starve following such injuries.

The Altestadt at Heidelberg boasts the longest pedestrianised street in Germany, perhaps in Europe. The Hauptstrasse stretches two kilometres. Cafés, restaurants and bars cluster towards the Cathedral end, shops towards the Bismarkplatz, where a last surviving member of the genus Woolworth still lives.

From Bismarkplatz you can take a tram to the end of the line, plus a linking bus to the Versailles-like palace and gardens of Schloss Schwetzingen. Here the pretension of kings, and the vision of Nicolas de Pegage assembled, in the latter half of the eighteenth century, battalions of trees, trimmed to within an inch of their barks, lace-works of waterways and box-hedged gardens, and several follies, not to mention the pink-painted Palace itself. The bright green parakeets arrived later. Traffic approaching across the Schlossplatz must do so at a funereal pace, though I saw one speeding car, mobile phone clamped to the driver’s ear – a right hand drive, bearing UK plates, of course.

Heidelberg’s own castle teeters precipitously above the old town, like a piece of badly scaled CGI. Its towers were ruined centuries ago, but they still seem precarious. From the castle gardens views over the Altestadt to the newer city out on the plains beyond defy bad camera-work. The Neckar, slow, broad, and black on a cool March morning, flows below, unconcernedly. On its far bank, behind well kept villas, rises the Heiligenberg, on which three ruins are worth a visit. Two belong to the city’s religious history, a church and a Basilika, associated with the Klosterhoff Abbey a couple of miles upstream – where they brew a range of organic beers. It is the third that catches the imagination, billed as a Celtic Hohenseidlung, and Thing Stadt. A stone amphitheatre, built in the nineteen thirties, tier upon tier of stone terraces look down upon a raised platform backed by a blockhouse-like podium, with curving stone staircases to each side. I triedBerkeley chorus line, but the image of flags and banners, of searchlights and flames, and of eight-thousand black uniformed Nazis seig-heiling could not be expunged. We were on the hiltop, yet, surrounded by trees, we were in a basin from which there was no view out.

Walking back down to the city, the bells of its many churches ringing, the Woolworth sign bright and readable in the distance, the slow flow of the dark river with its long, wide freight barges, slowly drew me back to the present. People in the Altestadt are friendly and welcoming. This is a University City, and has been one for six hundred years. That’s still a thousand times younger though, than that jaw.