Dusseldorf or Frankfurt?

Neither city is a beach destination, and neither river is for swimming. Düsseldorf's Rhine has sandy stretches that look tempting, but strong currents and barge traffic make it dangerous. Frankfurt's Main banks are a place to sit with a drink, not to swim. In both cities a summer swim means a lake, and the two lakes feel quite different.

Düsseldorf's Unterbacher See is inside the city limits on the south-east side, a park-like spot where you lie on the grass between dips. Frankfurt's Langener Waldsee is a flooded gravel pit out in the woods to the south, with sand at the water's edge, a forest setting and water that turns pleasantly warm in July and August. Both cities are a long day's travel from the sea, and Düsseldorf's nearest coast is the chilly Dutch North Sea.

Düsseldorf is the more rewarding place to eat, because it has two strong traditions where Frankfurt has one. The Altstadt brewhouses serve sauerbraten, pork knuckle and the Halve Hahn with brown mustard, and the Japanese community around Immermannstrasse adds queues for ramen, izakaya and Japanese bakeries that are rare in Germany.

Frankfurt's own cooking centres on the apple-wine taverns of Sachsenhausen, with Grüne Soße and Handkäs mit Musik at long shared tables. The Kleinmarkthalle is a fine stop, and the Bahnhofsviertel offers cheap international food, but the local repertoire is small and nothing matches Düsseldorf's Japanese quarter.

The two are close, but their strengths differ. Düsseldorf is a modern-art city, with the Klee collection at K20, the walk-on net under K21's glass dome, the Kunstpalast and galleries shaped by its art academy. Its finest historic site, the rococo Benrath Palace, lies out in the suburbs.

Frankfurt has more breadth and more history in its centre. The Museumsufer lines both banks of the Main, with the Städel as its masterpiece, and the reconstructed Römer, the cathedral, the Paulskirche and Goethe's birthplace are all a short walk apart, overlooked by Germany's only real skyline of towers.

Düsseldorf has the busier and more sociable night out. Hundreds of pubs and brewhouses are packed into the Altstadt, where weekend crowds drink Altbier standing in the lanes well past midnight, and Carnival turns the whole city into a party for days. Clubbing, though, is modest.

Frankfurt is quieter overall and comes alive mainly at weekends, but it has the more serious clubs. The techno and house tradition it shares with Offenbach still runs, and the Bahnhofsviertel's cocktail bars and late kiosks offer a grittier kind of night than anything in Düsseldorf.

Frankfurt has the better outdoors. The Taunus rises just beyond its northern suburbs, with beech forest and the 880m Großer Feldberg under an hour away, and the Stadtwald is a large forest inside the city. The Rheingau vineyards and the Rhine Gorge are within easy reach.

Düsseldorf's landscape is flatter and gentler: grassy Rhine meadows with sheep on the dykes, Grafenberg forest and the wooded Neandertal. The Bergisches Land's hills are half an hour away, but nothing here compares with the Taunus on the doorstep.

Both are excellent bases, and Frankfurt has the edge thanks to its place at the hub of the high-speed network. Heidelberg, the castle-lined Rhine Gorge and Würzburg's Residenz are all within easy reach, and closer in lie Mainz, Wiesbaden, Darmstadt and the imperial cathedrals of Speyer and Worms.

Düsseldorf's options lie in the dense Rhine-Ruhr region instead. Cologne is under half an hour away, with Bonn and the Brühl palaces beyond, and the Zollverein colliery in Essen, Aachen and Dutch Maastricht give it a more industrial and cross-border mix.

Both cities are equally easy with children: safe, compact, and with trams that take buggies without fuss. Düsseldorf's Aquazoo Löbbecke Museum, the Rheinturm and the free Grafenberg game park are its draws, and Phantasialand and Movie Park are within about an hour. Frankfurt answers with the Senckenberg's dinosaur hall, a central zoo, the Palmengarten and skyline boat trips on the Main.

There is almost nothing between them. Both have flat, walkable centres, integrated regional networks with confusing fare zones, and fast rail links to the airport. Frankfurt's main station connects straight to the high-speed lines, which helps for longer trips. Düsseldorf's Rhine promenade makes walking between the Altstadt, the Kö and the Japanese quarter especially pleasant.

Düsseldorf is the stronger shopping city. The Königsallee, with its canal, luxury flagships and arcades, is a reason to visit in itself, and the city's fashion-fair history shows in its department stores and well-dressed crowds. Flingern's boutiques and the Japanese quarter's stationery and homeware add character.

Frankfurt is good for everyday shopping on the Zeil, with luxury houses around Goethestraße and independent shops on Berger Straße and Schweizer Straße. The Saturday flea market on the Main is fun, but nothing here draws shoppers the way the Kö does.

The two cost much the same, and in both cases it is the hotels that do the damage, especially during trade fairs. In Frankfurt, weekends and summer can be noticeably cheaper as the business crowd leaves, and the Museumsufer pass helps. In Düsseldorf, brewhouse meals and Japanese noodle bars keep eating costs down away from the Königsallee.

Frankfurt has the stronger stage. Its opera company is one of Germany's most respected, known for adventurous productions, and the Alte Oper hosts the radio symphony orchestra and touring ensembles. An English-language theatre and contemporary dance at Mousonturm also help visitors who do not speak German.

Düsseldorf still offers a deep programme, with the Deutsche Oper am Rhein, the domed Tonhalle and the Schauspielhaus. Its distinctive extras are political cabaret and its place in electronic music as the birthplace of Kraftwerk.

Frankfurt is better placed for a restful break, because classic spa towns ring the city. Bad Homburg's thermal baths sit at the foot of the Taunus, and Wiesbaden's Art Nouveau Kaiser-Friedrich-Therme, fed by hot springs, is under an hour away.

Düsseldorf relies on the sauna areas of its public pools, which are mixed and without swimwear, with thermal complexes and Aachen's springs further afield. Its slower pace and the Japanese garden in Nordpark make it pleasant enough for an easy few days.