Vienna or Zagreb?

Neither city has a sea shore, but Vienna has much better summer bathing. The Danube Island gives about 20km of grassy banks and free swimming spots, the warmer Alte Donau has old lidos such as the Gänsehäufel, and the U-Bahn takes you to both.

Zagreb's swimming is limited to Jarun and Bundek, two lakes with pebbly shores that are fine for cooling off. The Adriatic is about two hours' drive away, so if you want sea and sand, plan a separate stay on the coast.

Vienna has the richer table. Its cooking is a cuisine in its own right, from schnitzel and Tafelspitz to Sachertorte, and the grand coffee houses are a reason to visit in themselves. Wine taverns in Grinzing and Stammersdorf pour wine grown inside the city.

Zagreb's cooking is hearty and Central European in feel. Try štrukli, turkey with mlinci and fresh cheese with cream from the Dolac stalls, then join the Saturday coffee promenade around Flower Square. Neither city is strong on international food, and Zagreb has fewer serious restaurants.

The difference here is large. Vienna is a former imperial capital, with the Hofburg, Schönbrunn, St Stephen's and the Ringstrasse. Its museums are world class, with the Kunsthistorisches, the Belvedere and the Albertina, and Otto Wagner and the Secession add a second great era. It fills a week without effort.

Zagreb's heritage is pleasant and on a smaller scale. The medieval Upper Town has St Mark's tiled roof and the Stone Gate, and the Austro-Hungarian Lower Town is laid out around the Green Horseshoe of parks and squares. Mirogoj cemetery and the Museum of Broken Relationships are memorable, but two days cover the city.

Both cities go out in a relaxed way rather than a wild one, and they differ mainly in setting. Vienna's evenings move between bars under the Gürtel railway arches, deckchair bars on the Danube Canal and slow evenings at a wine tavern. Its winter ball season, when visitors can buy tickets to formal balls in palaces, has no equivalent in Zagreb.

Zagreb's nights centre on café-bars that switch from coffee to drinks. The main strip is the terrace-lined Tkalčićeva, and in summer people move on to the lakeside clubs at Jarun. Its students keep alternative venues going all year.

Both cities have green country close at hand, but of different kinds. Vienna's walks climb through vineyards to the Kahlenberg, the Donau-Auen floodplain forest can be explored by boat, and the flat Danube cycle paths lead to the Wachau. Real limestone mountains, the Rax and Schneeberg, are about 90 minutes away.

Zagreb's mountain starts at the edge of town. A tram and a short bus ride bring you to the beech woods and mountain huts of Medvednica, which rises to about 1,030m at Sljeme and has a small ski slope in snowy winters. The lakes and waterfalls of Plitvice make a long day out.

Vienna has the stronger list, and most of it is easy without a car. Bratislava is about an hour away by train or Danube boat. The Wachau has Melk abbey and Dürnstein among its vineyards, and Baden, Eisenstadt and Brno are all within easy reach.

Zagreb's best trips go north into Zagorje, to Trakošćan castle and the baroque town of Varaždin, with Samobor and Karlovac closer in. These make pleasant days out, but none is as famous as Vienna's best. Several of them, along with Plitvice, are much easier with a hire car.

Vienna is the far easier city for children. Schönbrunn Zoo, the Prater rides and the shark tanks at Haus des Meeres give a full programme in good weather. The Natural History Museum, the Technical Museum and ZOOM cover the rainy days.

Zagreb is safe, flat in the Lower Town and easy with a pushchair. The Maksimir zoo, the Tesla technical museum and the tiny funicular are good for a day or two. With no aquarium or theme park, it suits a short, relaxed family stop better than a trip built around children.

Both centres are compact enough to walk, but Vienna's transport goes much further. Five U-Bahn lines, trams and buses share one ticket, the U-Bahn runs all night at weekends, and even the vineyard villages can be reached by public transport.

Zagreb relies on its blue trams and buses, and the trams slow down in rush-hour traffic. The funicular saves the climb to the Upper Town, but the cobbles up there are steep. You will need a car only for Zagorje and Plitvice.

Vienna offers more, especially at the top end. Luxury houses line the Kohlmarkt and Graben, Mariahilfer Strasse and the Neubau side streets have everyday fashion and independent designers, and Augarten porcelain, crystal and Loden make lasting gifts. Its Christmas markets add a seasonal reason to shop.

Zagreb's shopping is everyday, concentrated along Ilica, with little luxury. Its souvenirs are distinctive, though: red licitar hearts, Croatian neckties, lace and truffle products, plus food from Dolac to take home.

Zagreb is clearly the cheaper city. Rooms, trams, museum entry and simple meals all cost less, although cocktails and the best hotels cost about what they would in Western Europe.

Vienna costs more, mainly because the major palaces and museums charge full admission. Some things soften the bill: cheap standing places at the State Opera, transport passes, free palace gardens and the buffets at wine taverns.

This is where the two cities are furthest apart. Vienna is one of the world's great music cities, with the State Opera on most nights, the Philharmonic in the Musikverein's Golden Hall, the Konzerthaus and the Volksoper. The Vienna Boys' Choir sings Sunday Mass, and Mozart, Haydn and Beethoven are played all year.

Zagreb has a proper season of its own. The ochre Croatian National Theatre stages opera and ballet, the Lisinski hall is home to the Zagreb Philharmonic, and there are summer concerts in Upper Town courtyards. Much of the theatre is in Croatian, though, and little of it is internationally known.

Vienna makes rest easier. Therme Wien's thermal pools and the Art Deco Amalienbad are inside the city, and Baden's sulphur springs are about half an hour away.

In Zagreb itself, spa options are mostly hotel wellness floors. For thermal pools you need the Zagorje spa resorts, about an hour north. Both cities share a slow café rhythm, Vienna in its coffee houses and Zagreb on its terraces and quiet Upper Town lanes.