Frankfurt or Rotterdam?

Rotterdam at least has a real shore. Hoek van Holland is a broad sandy strand with dunes behind it and container ships passing close by, and the metro gets you there in under an hour. The catch is the cool, windy North Sea, so most people walk the beach rather than swim.

Frankfurt is far from any coast. On a hot day the choice is an outdoor pool or a gravel-pit lake such as the Langener Waldsee in the southern forest, which is pleasant in July and August but no substitute for the seaside.

The food is equally good in both cities but very different. Frankfurt is about its own regional tradition: long tables in the apple-wine taverns of Sachsenhausen, stoneware jugs of tart cider, Grüne Soße and Handkäs, and the Kleinmarkthalle for sausages and Hessian produce.

Rotterdam's best eating comes from its port and its immigrant communities, not from Dutch cooking: Surinamese roti, Turkish bakeries, and Cape Verdean and Indonesian kitchens, with the Markthal and Witte de Withstraat as starting points. Go to Frankfurt for a local ritual, and to Rotterdam for range.

Both centres were largely destroyed in the war, and each makes about two or three days of sightseeing, but they rebuilt in opposite directions. Frankfurt reconstructed its gabled Römer, its old-town lanes and the Paulskirche, and its real draw is the Museumsufer, led by the Städel and backed by the Schirn and Senckenberg.

Rotterdam chose to build something new, and the buildings themselves are the sights: the Erasmus Bridge, the Cube Houses, the Markthal vault and the mirrored Depot Boijmans. Its museums are good rather than great, so pick Frankfurt for galleries and Rotterdam for architecture.

Both are weekend cities that go quiet early in the week, and both have a club history rooted in electronic music. Frankfurt's evenings are more about bars. The gritty Bahnhofsviertel has cocktail bars and late kiosks, Sachsenhausen has cider taverns and rowdier pubs, and Berger Straße has relaxed neighbourhood bars.

In Rotterdam the clubs are the stronger part. Gabber was born here, and harbour and warehouse techno nights draw people from across the Netherlands. Its bar terraces on Witte de Withstraat and the Oude Haven are more modest, though students keep weeknights from going completely dead.

Frankfurt has far more landscape to offer. The Taunus starts at the northern suburbs, with the Großer Feldberg at about 880m, Roman frontier trails and mountain-bike routes under an hour away, plus the Odenwald and the Rhine Gorge vineyards further out.

Rotterdam's outdoors is flat and watery: the Kralingse Bos lake, bike rides along dykes into the polders, and canoeing among the tidal creeks of the Biesbosch. It suits cyclists and birdwatchers, but anyone hoping for a proper hike will be better off in Frankfurt.

Both sit at the hub of a fast rail network, so either makes an excellent base. From Frankfurt the trips run to castles and wine: Heidelberg's castle ruin, boats through the Rhine Gorge, Cologne's cathedral and Würzburg's Residenz.

From Rotterdam they run to canal towns and Old Master cities: Delft and The Hague within a short ride, Amsterdam and Haarlem in about an hour, the Kinderdijk windmills by water bus, and Antwerp, Bruges or Ghent across the Belgian border.

Both cities work for a few days with children, but in different ways. Frankfurt's centre is compact, so short legs don't have far to walk, and the trams and S-Bahn take pushchairs without fuss. Its best rainy-day answer is the hall of dinosaur skeletons at the Senckenberg, which nothing in Rotterdam quite matches, and the Palmengarten glasshouses make a quiet half-day. Its central zoo fits into a walk rather than being a day out in itself.\n\nRotterdam's sights are further apart, but the streets are flat, the pavements broad and cycle paths run separately almost everywhere, so the distances are easy with a pushchair or a child on a bike.

That is what makes it the more relaxed city to move around as a family. Blijdorp, with its ocean halls, is a bigger zoo day than Frankfurt's. At the Maritime Museum children play at running a harbour, while at the Senckenberg they mostly look, and the water taxis turn a river crossing into a ride. For an outing, Madurodam's miniature Netherlands is a short train ride away, where Frankfurt offers the wildlife park at Kronberg and a small fairy-tale park in the Taunus.

Transport is equally good in both, and neither needs a car, but on foot they feel different. Frankfurt's sights sit close together, with the Römer, the cathedral and the Museumsufer minutes apart, and its airport is about a quarter of an hour from the centre by train.

Rotterdam's postwar centre is spread out, with wide, windy roads between the sights, so people mix walking with trams or a bike, which is how locals travel. Water taxis across the Maas make the river part of the network.

They are on a par, with good high streets and no real speciality in either. Frankfurt has the edge for luxury: Goethestraße's fashion and jewellery houses sit next to the department stores of the Zeil, and Berger Straße has independent shops.

Rotterdam is thinner on designer labels. Its strengths are the early pedestrian street of the Lijnbaan and the vintage, record and design shops along the Meent and the Nieuwe Binnenweg.

Overall the two cost about the same, but the costs fall in opposite places. In Frankfurt the hotels are the expense, especially during trade fairs, while cider taverns, Turkish grills and market stalls keep meals cheap. Weekends and summer bring room rates down.

In Rotterdam beds are easier to find and kinder to the budget than in Amsterdam, but eating and drinking out cost what they do across the Netherlands. Surinamese snack shops and Markthal counters are the way to save.

Frankfurt offers more for an evening out. Its opera company is among Germany's most respected, the rebuilt Alte Oper is home to the radio symphony orchestra, and the Schauspiel, the contemporary dance stages and an English-language theatre add depth. Its season quietens in summer.

Rotterdam has no resident opera, and much of its theatre is in Dutch. It does have a fine philharmonic at De Doelen, and in July it hosts the North Sea Jazz Festival, one of the world's great jazz weekends.

Frankfurt has more for a slow day, thanks to the spa towns around it. Wiesbaden's Kaiser-Friedrich-Therme is fed by hot springs, Bad Homburg has a spa park and thermal baths, and Bad Nauheim keeps up the old practice of taking the waters.

Rotterdam relies on the Dutch sauna tradition instead. Large complexes on the edge of the city have pools and gardens, and the sauna areas are mostly textile-free. In the centre there are hotel spas, or a walk by the Kralingse Bos lake.