Heidelberg or Interlaken?

Neither is a beach destination, but Interlaken at least has water worth swimming in. In July and August Lake Thun warms to around 21°C, with grassy lidos and shingle shores at Neuhaus and towards Spiez. Lake Brienz, a glacial turquoise, offers a colder dip at Bönigen, with snow peaks behind.

Heidelberg has nothing to match that. The Neckar is not for swimming, so a hot afternoon means one of the town's outdoor pools or a gravel-pit lake on the Rhine plain, about half an hour away.

Heidelberg eats better, mostly because of its wine. Riesling and Pinot from the Bergstrasse and the Palatinate villages are poured in taverns alongside Schäufele, Maultaschen and, in spring, white asparagus. The side streets of the Altstadt and Neuenheim are a better bet than the Hauptstrasse.

Interlaken's restaurants serve fondue, rösti and a range of Asian and Middle Eastern dishes to a passing crowd, reliably but without much depth. The best eating there comes from the mountains: cheese from an Alpine dairy or lunch on a hut terrace above Grindelwald.

This is the widest gap between the two. Heidelberg has a red sandstone castle ruin above a baroque old town, the Old Bridge with its gate towers, the Church of the Holy Spirit, and Germany's oldest university with its graffiti-covered Student Prison. That is enough for a full day or two.

Interlaken's sights amount to the grand hotels and the Kursaal along the Höheweg and a few old timber houses in Unterseen. For history and museums you take the train, and Bern is the most rewarding place to go.

Heidelberg has the livelier evenings, thanks to its students. The small pubs of the Untere Strasse and the old student taverns fill up late in term time, although outside term the town goes quiet early. Interlaken has a handful of backpacker pubs and basement clubs plus the casino in the Kursaal, and most visitors are in bed early for the morning train up the mountain.

Heidelberg's outdoors are pleasant and close at hand. There are forest trails from the Königstuhl, the view from the Philosophers' Walk, cycling along the Neckar, and the sandstone crags of the Palatinate Forest an hour west. It is green, rolling country rather than high ground.

Interlaken is on another scale. Within an hour are the Eiger, Mönch and Jungfrau, the waterfalls of the Lauterbrunnen valley and the Jungfraujoch at 3,454m above the Aletsch glacier. Paragliding, canyoning and rafting all start from town, and skiing takes over in winter. Only low cloud spoils it.

Both are excellent bases, and the difference is in what you go out to see. From Heidelberg the outings are to historic towns: the cathedrals of Speyer and Worms, the palace at Schwetzingen, Maulbronn's walled monastery and the wine villages of the Palatinate. Frankfurt is easy to reach, and Strasbourg works as a long day.

From Interlaken the trips are journeys by lake and mountain railway. Bern's arcaded old town is under an hour away, paddle steamers stop at the castles of Thun, Spiez and Oberhofen, and there is the open-air museum at Ballenberg. Lucerne is reached on the scenic line over the Brünig Pass.

Interlaken comes out ahead because the transport is half the fun. Children get rack railways, gondolas and lake steamers, then playgrounds, summer toboggan runs and cliff walks at the summit stations, plus the St Beatus caves. Rainy days are the weak spot, and the highest summits may not suit very young children.

Heidelberg is easier to fill when it rains. It has its zoo, the fairy-tale park on the Königstuhl, and the aircraft and submarine at the Technik Museum Speyer nearby. The cobbled, sloping Altstadt is hard work with a pushchair, though.

Interlaken's network is the more impressive. Mainline trains, narrow-gauge mountain lines, cog railways, gondolas and lake steamers connect neatly, so the whole Jungfrau region works without a car, and the flat town takes about twenty minutes to walk end to end. The most popular trains can be crowded in summer.

Heidelberg is simple too. The Altstadt is walkable, a funicular climbs to the castle, and one fare covers trams and the S-Bahn across the Rhine-Neckar area. The main station is well west of the sights, however, and the walk up to the castle is steep.

Neither is a shopping destination, but Heidelberg gives you more to browse. The long Hauptstrasse has department stores at one end, there are independent bookshops and boutiques in the side lanes, and Bergstrasse wine makes the best thing to take home.

Interlaken's Höheweg is mostly watch stores, army knives and souvenirs aimed at tour groups. Woodcarving from Brienz is the one local craft worth carrying back.

Heidelberg is far easier on the wallet. Rooms can be scarce and dear at busy times, which many visitors get around by staying in Mannheim. Meals in student cafés and taverns are reasonable, though, and the regional ticket makes day trips cheap.

Interlaken charges full Swiss prices for everything. The mountain railways, above all the line to the Jungfraujoch, are what push the cost of a stay so high. Picnics, transport passes and walks from the valley floor help, but doing the region properly is expensive.

Heidelberg has a real season. The municipal theatre stages opera, drama and dance, the philharmonic orchestra gives regular concerts, the Heidelberger Frühling brings chamber music in spring, and in summer there are performances in the castle courtyard. Mannheim's larger opera house is twenty minutes away by train.

Interlaken has the amateur open-air William Tell each summer, folklore evenings with alphorns and yodelling, and occasional concerts in the Kursaal. Anyone wanting an orchestra goes to Bern.

Neither town has thermal baths of its own, so the difference is in how you rest. In Heidelberg it means evenings on the Neckar meadows in Neuenheim, quiet forest paths and slow evenings in wine taverns. The saline pools of the Kraichgau spa towns are half an hour away, and Baden-Baden is about an hour.

Interlaken relies on the spas of the grand hotels on the Höheweg and on early mornings by the lake and slow steamer crossings. The centre is busy with coach groups, so people looking for quiet stay in Wengen, Mürren or the lakeside villages.