Ljubljana or Vienna?

Neither city is a beach destination, and in both a swim is a summer afternoon rather than the point of the trip. The difference is where the water is. In Vienna it is inside the city: the Danube Island's long gravel banks and the calmer, warmer Alte Donau with its old lidos are a U-Bahn ride from the centre.

From Ljubljana you mostly travel to swim: to Lake Bled about an hour away, to colder, clearer Bohinj, or to the Adriatic at Piran, where the shore is concrete and pebble rather than sand. The Sava on the city's edge is the only option close at hand.

Both cuisines are hearty and regional, but Vienna's has more depth and more rituals around it. Schnitzel, Tafelspitz, and the strudel and Sachertorte of the grand coffee houses form a cuisine of their own, and the Heuriger taverns on Grinzing's slopes pour wine grown inside the city.

Ljubljana is simpler: štruklji, Carniolan sausage and jota at gostilna inns, and a riverside market of cheeses and pumpkin-seed oil. Its strength is wine by the glass from Vipava or Brda, including the orange wines of the west, but you run through the choice sooner. Neither city has much range in international food.

This is a wide gap. Vienna is an imperial capital with the Hofburg, Schönbrunn, St Stephen's and the Ringstrasse, and its museums are world-class: Bruegel at the Kunsthistorisches, Klimt at the Belvedere, Schiele at the Leopold. Add the Secession and Otto Wagner's Jugendstil buildings, and a week is barely enough.

Ljubljana's appeal comes from one architect's vision: Plečnik's bridges, colonnades and library, set in a small baroque and Secession old town below the castle. Its galleries are pleasant but not essential, and two or three days cover it all.

Vienna has more choice after dark, though neither is a party capital. Bars under the Gürtel railway arches, the Bermuda Triangle in the old town, deckchair bars on the Danube Canal and electronic nights in old industrial spaces give it range, and the winter ball season is something Ljubljana cannot match.

Ljubljana's evenings centre on the terraces along the Ljubljanica, which are livelier in term time thanks to the students, and on the scruffy late clubs of Metelkova. It is a good town for a drink by the river, but quiet after midnight on weekdays.

Ljubljana is the stronger base for the outdoors because real mountains are close. The Kamnik-Savinja Alps are under an hour away and the Julian Alps and Triglav National Park about an hour. Beyond them lie rafting on the Soča, the Vintgar gorge and the karst caves of Postojna and Škocjan, with small ski resorts within reach in winter.

Vienna's countryside is gentler: the beech-covered Vienna Woods, vineyard trails up to the Kahlenberg, the Donau-Auen floodplain forest and flat Danube cycle routes such as the Wachau path. Its nearest proper peaks, the Rax and Schneeberg, are about an hour and a half away.

Both are well placed for excursions, but the trips are of a different kind. From Ljubljana they are mostly about Slovenia's scenery and small towns: Bled's island church, painted Radovljica, Predjama Castle in its cliff and the coast at Piran, with Trieste and Zagreb at a stretch. A car helps for the smaller places.

From Vienna they are more about other cities and river landscapes, easily reached by train or boat: Bratislava within an hour, the abbeys and vineyards of the Wachau, Haydn's Eisenstadt and Brno over the Czech border.

Vienna has much more for children. Schönbrunn Zoo, the Prater's Ferris wheel and rides, the Haus des Meeres aquarium and the Natural History and Technical Museums keep a family busy in any weather, and summer bathing on the Danube Island adds more.

Ljubljana is gentle rather than exciting: a flat, car-free centre that suits pushchairs, the castle funicular, the dragons on the Dragon Bridge and the puppet theatre. With no aquarium or theme park, families will have seen it in a few days.

Both centres are walkable, but Vienna adds a full public transport network. Five U-Bahn lines, a dense tram network and buses share one ticket, run through the night at weekends, and reach Schönbrunn, the Prater and the vineyard villages without a car.

Ljubljana has no metro or tram, and in its compact centre you will rarely miss one. Leaving town is the weak point: intercity buses are quicker than the slow trains, and the remote valleys need a hire car.

Vienna has the bigger and more polished range. Luxury houses line the Kohlmarkt and Graben, high-street brands fill Kärntner Strasse and Mariahilfer Strasse, and independent designers work in Neubau. Gifts such as Augarten porcelain and Loden coats are worth buying, and the Christmas markets give a seasonal reason to shop.

Ljubljana is small-scale and local. It is best for honey, pumpkin-seed oil, coastal salt, Idrija lace and the Sunday flea market on the embankment, with a few boutiques around Trubarjeva street.

Ljubljana is the cheaper stay of the two, especially when eating out: set lunch menus at the inns, fairly priced local wine and almost nothing spent on transport. Its weak spot is hotels, since central rooms are few, and in July and August they are priced like those in Western Europe.

Vienna asks more for meals and for its palaces and museums, which charge full admission. Free gardens and churches, good-value transport passes and the State Opera's standing places soften the bill.

Here Vienna is on another scale, and for many visitors music is the reason to come. The State Opera, the Vienna Philharmonic at the Musikverein, the Konzerthaus, the Volksoper and the Burgtheater put on a full programme every night in the city of Mozart, Beethoven and Schubert.

Ljubljana does well for its size, with the Slovenian Philharmonic, the national opera and ballet, Cankarjev dom and the summer festival in Plečnik's Križanke courtyard. That is enough for an evening or two, but most theatre is in Slovene.

Proper bathing is easier to reach from Vienna. There are the thermal pools of Therme Wien and the Art Deco Amalienbad in town, and the sulphur springs of Baden are half an hour away. The coffee houses and evenings at vineyard taverns set a slow pace too.

Ljubljana itself has less: an indoor water park and a few hotel spas, with the country's thermal spa towns up to an hour's drive away. What it gives instead is quiet, a green, car-free centre and long afternoons at riverside cafés.