Rothenburg ob der Tauber or Strasbourg?

Neither is anywhere near the sea, and swimming is a hot-afternoon extra in both. The difference is how you get to the water. In Strasbourg you take the tram to the Baggersee or another lifeguarded gravel-pit lake. From Rothenburg it is the town's outdoor pool or about an hour's drive to the grassy shores of the Altmühlsee.

Strasbourg is the much better place to eat. Alsatian cooking takes from both France and Germany, so you get choucroute, baeckeoffe and tarte flambée in wood-panelled winstubs, along with a fine-dining tier, foie gras and markets full of Munster and charcuterie. As in Rothenburg, the tourist menus are concentrated around the main sights.

Rothenburg's cooking is hearty but narrow: Schäufele, bratwurst and dumplings, with Silvaner served in the squat Bocksbeutel bottle. Many places around the Marktplatz cook for coach parties, so the better meals are found in family guesthouses and wine taverns away from the square.

Strasbourg has more to see and takes longer to see it. Its pink sandstone cathedral with the astronomical clock, the Grande Ile, Petite France and the German-built Neustadt make up a UNESCO-listed ensemble, and the Palais Rohan, the Oeuvre Notre-Dame and the modern art museum add real depth.

Rothenburg is a single, complete experience: walls you can walk round, the Plönlein, the view from the Rathaus tower, and Riemenschneider's Holy Blood Altar in St Jakob's. It is unusually intact, but it is done in a day, while Strasbourg needs two or three.

Strasbourg at least offers an evening out. A large university keeps the Krutenau and Place Saint-Étienne busy with student bars and beer cellars, and the riverside terraces stay full on summer nights, though there are few clubs and nights rarely run late.

In Rothenburg the evening's event is the night watchman's lantern tour, followed by a glass of wine in an inn before the lanes go quiet.

Rothenburg's countryside starts at the walls. Paths lead down into the Tauber valley past mills and meadows, and the river's cycle path heads off through vineyards. It is all gentle and green, with no high ground or wild country.

Strasbourg reaches much further. It is a flat cycling city with riverside forests where storks and beavers live, and within about an hour you can be on the forest trails and castle ridges of the Vosges or hiking the steeper fir-covered heights of the Black Forest.

Both are strong bases, and Strasbourg is the stronger and easier one. Colmar is half an hour away by train, the Alsace wine villages and Haut-Koenigsbourg are close by, and Baden-Baden, Freiburg, Basel and Nancy add a second country and a wider range.

Rothenburg's excursions are the Romantic Road's other walled towns, Dinkelsbühl and the crater-ringed Nördlingen, plus Würzburg's Residenz and Nuremberg about an hour away. Because of the sparse branch-line trains, you really need a car for them.

Strasbourg gives children more to do and makes it easier for parents. There are boat trips round the Grande Ile, the storks and rowing boats in the Orangerie, the hands-on Le Vaisseau science centre and the trams. Europa-Park, about an hour away, can fill a whole day.

Rothenburg delights children for a short time. Walking the ramparts, following the night watchman and the shame masks in the Crime Museum all go down well, but after a day or two there is little left, and the cobbles are tough going with a pushchair.

Both centres are best on foot, but Strasbourg's island is flat and largely pedestrianised, while Rothenburg's lanes are cobbled and the climb back up from the Tauber valley is steep. Strasbourg also has a tram network, a tram line over the Rhine to Kehl and plenty of separated cycle lanes, so you never need a car in the city.

Rothenburg's station sits at the end of a branch line, so most journeys involve a change at Steinach, and the buses to nearby villages are sparse. To explore beyond the walls, you will want a car.

Rothenburg sells one thing very well: Christmas, all year round, with glass baubles, nutcrackers and Erzgebirge carvings along the Herrngasse, plus teddy bears and cuckoo clocks. Beyond that, there is little ordinary shopping.

Strasbourg has a fuller range, with chain stores and a department store around Place Kléber and independent shops, delis and bookshops near the cathedral. The things to take home are Soufflenheim pottery, printed linens and Alsace wine. Both towns have celebrated Christmas markets, and Strasbourg's is one of the oldest in Europe.

The two cost about the same overall, and in both the price of a room decides the bill. In Rothenburg you pay a tourist premium to sleep inside the walls, so staying outside them or in a nearby village saves a good deal. In Strasbourg, hotel prices jump during the Christmas market and when the European Parliament is sitting, but the trams, the cathedral and wine by the pichet stay cheap.

Strasbourg has a proper arts season. The Opéra national du Rhin, the Philharmonic and the Théâtre National de Strasbourg all perform regularly, and the Musica festival makes it a centre for contemporary music.

In Rothenburg, performance mostly means history: the costumed Meistertrunk play, summer open-air theatre and organ concerts in St Jakob's. On most nights, dinner is the evening.

Strasbourg is better set up for unwinding. The tiled Bains municipaux with its hammam is right in the city, and Baden-Baden's Friedrichsbad and Caracalla baths are less than an hour away. December is the exception, when the market crowds fill the centre.

Rothenburg's calm comes from its emptiness at dawn and after the coaches leave. For thermal pools you have to drive to the salt-water Franken-Therme at Bad Windsheim or to Bad Mergentheim.