Compared to the small towns which dot the Neckar river, Heidelburg is a big old city (with 160,000 residents today and founded in 1196). It has a well-defined old part (Altstadt) which covers about 3km along the river between Karl's Tor and the Theodor-Heuss-Brücke with the famous Alte Brücke in between. The Altstadt is dominated by Heidelberg castle which itself spans some 500m and sits 100m above the river. The 'hill' above that (Königstuhl) is a total of 450m above the town and the summit offers a panoramic viewpoint over the entire Neckar valley, the city, and the Rhine plain.

In terms of what to do, there is a well-specified walking route around the old city which takes in more than 30 of the major sights, though it is easy to become overwhelmed with one famous building after another. The Altstadt in particular is replete with cafes and restaurants and as you move further east beyond the Alte Brücke, particularly along the Hauptstraße, these give way to shops with familiar brand names.

That trail aside, the dominant attraction by far is Heidelburg Castle. It's possible to walk up a path to make the visit but there is a great funicular railway which can take you there instead and the price of the train includes entrance to the castle. For a little more, the funicular railway connects with a second railway to take you all the way to the top of Königstuhl which at €17 return total (May 2026) is reasonably priced compared with other funicular railways and gondolas around Europe.

One can easily spend a couple of hours at the castle and its grounds. In contrast, there is little to do at the Königstuhl peak unless you are fond of mountain biking through the view from the top is something to tick off your 'to-do' list.

Across the valley on the opposite side from Altstadt is a path known as Philosopher's Walk, so called as it provided a tranquil route for students in the 18th and 19th centuries to stroll, reflect and relax. At 100m above the river, it also provides great views of Heidelburg and the castle and I was able to take a blue-hour shot of the castle and town from this location. Today though, the trees along the route are very mature and good viewpoints are relatively few in number.

Views of Heidelburg including the Altstadt centre, the castle and the panoramas from Königstuhl peak and Philosopher's Walk, can all be seen here.