Karlovy Vary or Luxembourg?

Neither is a swimming destination, but Luxembourg gives a little more to work with on a hot day: designated bathing spots on the wooded shores of the Upper Sûre reservoir and the gravel-pit lakes at Remerschen in the Moselle valley.

Karlovy Vary's nearest equivalent is Lake Medard, a flooded mine near Sokolov, plus a few ponds in the hills. Its distinctive swim is in water warmed by the springs, in the outdoor thermal pool on the hillside.

Luxembourg eats much better. French cooking leads its restaurants, Belgian, German, Portuguese and Italian habits fill the brasseries and neighbourhood places, and there is a surprisingly deep tier of fine dining for a city of its size. The Moselle Rieslings and crémant poured by the glass are a pleasure in themselves.

Karlovy Vary sticks to hearty Czech cooking, roast pork, dumplings and svíčková with Pilsner-style beer, and its two treats are the warm spa wafers and Becherovka, the herbal liqueur born in the town. It is a place for cafés and cake rather than a reason to travel for the food.

Both are UNESCO-listed and both are seen comfortably in a couple of days, but the sights are of a different kind. Karlovy Vary is a set piece of spa architecture: pastel Belle Époque hotels climbing the Teplá valley, the colonnades over the springs and the Vřídlo geyser, with small museums on glass and Becherovka.

Luxembourg's draw is a fortress city on a rock, with the Bock casemates to walk through, the Grund below and the Grand Ducal Palace above. It also has the larger museums, the National Museum of History and Art and contemporary art at MUDAM on Kirchberg.

Luxembourg has the better evenings, though still on a small scale. Bars and a couple of clubs cluster at the Rives de Clausen, the Grund has riverside pubs in old stone houses, and Hollerich keeps later hours, with an international crowd of young professionals busiest on Thursdays and Fridays.

Karlovy Vary is largely asleep by eleven, its spa guests walking the promenade after an early dinner. The only real exception is the film festival week, when parties and outdoor bars fill the valley.

Both offer green, gentle country rather than drama, and the difference is in the kind of walking. In Karlovy Vary the beech and spruce forest starts at the edge of the spa quarter, with graded paths made for convalescents leading up to the Diana lookout, and the Ore Mountains add skiing at Klínovec in winter and easy canoeing on the Ohře.

Luxembourg brings its wooded gorges right through the city centre, and half an hour away the Müllerthal has mossy sandstone ravines and narrow rock passages. Beyond lie the Ardennes hills and the cycle paths along the Moselle vineyards, at their best in autumn.

Luxembourg wins on reach because three countries are on its doorstep. Roman Trier and the Gothic cathedral of Metz are each under an hour by train, Nancy is not much further, and at home there are the castle at Vianden, Echternach's abbey and the Moselle wine villages.

Karlovy Vary's outings are closer to home but well worth making. Loket's castle in its river loop is twenty minutes away, Mariánské Lázně and Františkovy Lázně complete the spa trio, and Bečov's medieval reliquary and Plzeň's breweries round it out. Prague is a long day by coach.

Luxembourg is the easier choice with children. The casemate tunnels and ramparts feel like an adventure, lifts take pushchairs down to the river quarters, and the natural history museum and Parc Merveilleux at Bettembourg are aimed at younger visitors.

Karlovy Vary charms children for a day or so with the geyser, tasting the warm springs, the funicular to the Diana lookout with its small animal enclosure and the spa wafers. After that, a town built for adults taking cures and its steep valley sides wear thin.

Luxembourg is the simpler place to move about, because trams, buses and trains are free across the whole country. The tram links the station, old town and Kirchberg, public lifts connect the levels of the city, and trains reach Vianden, Clervaux and the Moselle without a car.

Karlovy Vary is a walk along one long riverside strip, with buses and the funicular for the climbs. Its regional trains to Loket and the other spa towns are slow, and a car helps for the forests and villages.

Neither is a shopping destination, and each is best for a few local specialities. In Karlovy Vary that means Moser crystal, local porcelain and Bohemian garnets, sold alongside spa cups, wafers and Becherovka on the promenades of Stará louka and Tržiště.

Luxembourg leans to international luxury brands on the Grand-Rue and chains along Avenue de la Gare. Its souvenirs are Villeroy & Boch tableware and bottles of Moselle crémant, with a produce market on Place Guillaume II.

Karlovy Vary is far cheaper. The grand hotels and colonnade restaurants charge for the setting, but Czech pubs one street back keep meals at local prices, and rooms fall outside summer and the festival week.

Luxembourg is expensive for both sleeping and eating, with hotels priced for business travellers. Free transport, free museums and good-value lunch menus help, and many visitors save by staying in Trier or Metz instead.

Luxembourg has the stronger programme. The Philharmonie on Kirchberg hosts its own orchestra and touring soloists, the Grand Théâtre stages visiting opera and dance, and the Rotondes and summer concerts at Neimënster in the Grund widen the range.

Karlovy Vary's music grows out of its spa past. The symphony orchestra descends from the bands that played to spa guests and gives light classical concerts, some outdoors on the colonnades, while the ornate Fellner and Helmer theatre takes touring operetta and drama.

This is where Karlovy Vary pulls far ahead. The town exists to take the waters: guests drink from the springs along the colonnades as a prescribed cure, and dozens of spa hotels and sanatoria offer carbonated baths, peat wraps, massage and doctors' consultations, many with pools of warm spring water.

Luxembourg has no bathing culture of its own. Its spa is half an hour away at Mondorf-les-Bains, a pleasant day out, and otherwise it relies on hotel spas, the Kirchberg pool complex and quiet riverside walks.