With 231 shops in 33 countries and an annual turn-over of €15bn (£10bn), Ikea's world domination, at least as far as domestic interiors go, might suggest that Swedish style is all about chintz-free modernity. But though there is no shortage of excellent contemporary design, the Swedish capital is equally a city of opulence and rococo.
Here they call the style Gustavsk after the 18th-century Francophile King Gustav III, whose passion for its curvaceous lines made it fashionable. For Sweden remains a monarchy (albeit a bicycling one), whose crown insignia are evident everywhere: on the coins; on the bridges; and, most strikingly, woven into the carpet at the fabled Grand Hotel, which is itself "by appointment to HM the King". Luxurious and discreet, this is where heads of state, celebrities and Nobel laureates stay: everyone from the Dalai Lama and Sir Elton John to the ultimate Swedish screen goddess, Greta Garbo, who made it her home-from- home after she left Sweden for America in 1925.
Having uttered the immortal line "I want to be alone" in the movie Grand Hotel, she lived up to her reclusive reputation here. "She would lock herself in her room, and the only person she would allow in was the floor manager when he came with dinner," says the hotel historian, Lennart Jarnhammar. "Despite his discretion, she would hide in her bathroom till he put everything down and left."
The management remains a model of diplomacy, and the rooms are film-star fabulous. Even the harbour-view "standard" I stayed in had Gustavian grandeur, with its chandelier, damask curtains, rococo antiques and swagged bed (endorsed by Madonna in the guest book). Yet that paled in comparison with some of the public rooms. The Spegelsalen hall, for example, has gilding, garlands and glass modelled on the Hall of Mirrors at Versailles. The colonnaded Stromsalongerna has golden walls, and the Carl Larssen Rummet was decorated by one of Sweden's most celebrated artists in his student days. The faux-Renaissance style is a far cry from the cheerful pastel pastoral scenes for which he is famous.
You could hole up at the Grand quite happily in winter, with a blizzard outside, surveying the harbour traffic and people-watching from the clubby lobby bar. At this time of year, however, there is no excuse not to explore the islands, for Stockholm extends across 14 of them, a fragmented barrier which prevents Lake Malaren from leaking into the Baltic.
The nearest island a matter of minutes away, is Skeppsholmen, a cluster of handsome Baroque buildings that once served as Sweden's admiralty, and is now home to the Moderna Museet art gallery and adjoining architecture museum. For proper palatial architecture and ancient streets, you should make sure not to miss the island of Gamla Stan or Old Town.
It would be a shame, too, not to venture on to the water. So clean is it here, you will see people fishing from the Stadshusbron bridge by the City Hall. Along the embankment known as the Stromatan, there are helpful signs alerting you to the sort of fish you might expect to catch: salmon, sea trout, even the odd Arctic char. There are also city beaches for the very hardy (the water is chilly): try the Klippbad on Langholmen, directly west of Gamla Stan.
Better yet, catch a ferry from the Stadhuset jetty to Drottningholm, the Swedish Versailles and home of the royal family, an hour's trip along the lake to Lovon island. The monumental palace is handsome though dull, but its pavilions and folly-filled gardens - an "English park", with formal Baroque parterres, and, best of all, the court theatre - are a treat. Built in 1766 by architect C F Adelcrantz, who was never paid but was instead allowed to live in the theatre (hence the unexpected bedrooms for him and his servant at the front of the building), it's the most perfectly preserved Baroque theatre in existence and is still used for opera performances each summer season.
Even if the music doesn't appeal, an afternoon here is an intriguing lesson in 18th-century stagecraft. Join one of the backstage tours, and you will see extraordinary stage machinery constructed using maritime techniques based on rigging and capstans.
There is a wind machine, and another to create thunderclaps, which is made from a coffin full of stones.
The sublimely ornate auditorium is an exercise in deceit, with trompe l'oeil papier-mâché moulding, marbled wood and panels painted to look like curtains.
This spirit of exuberant theatricality extends to Adelcrantz's buildings in the grounds. Take the Guards' Tent, accommodation for dragoons contrived to look like a Turkish tent of billowing striped canvas. Or there is the exquisitely pretty little "Chinese" palace built as a birthday present to the queen, and flanked by four pavilions, one of which, the "Confidence", enabled the royal family to dine undisturbed by servants: the dining table was lowered through the floor to a kitchen, laden with the next course and raised again.
All of which, despite the still-high sun, which doesn't set in early August until about 9.30pm, was enough to put me in mind of dinner. Back at the Grand Hotel, Garbo may have opted for room service, but I was tempted by the smorgasbord in the Veranda restaurant. This, the only authentic fare left in the city that is served year-round (though the dishes change seasonally), is a cultural as well as a gourmet experience.
It's bad form to overfill your plate, or to take it back to the buffet (leave it on your table; someone will clear it) or to mix certain foods - fish with meat, hot with cold. Instead approach it as a multi-course tasting menu. I started with chanterelle soup. Then it was on to the herring, dressed and cured in half a dozen ways. After that, eel and salmon: hot-smoked, cold-smoked, gravadlax and cured with juniper. Smoked lamb and reindeer followed, then hot dishes: meatballs, and the cream, anchovy and potato confection called Jansson's temptation.
Finally, I had cheese (cumin-spiced kryddost and blue vasterbotten) and desserts involving cloudberries and lingonberries, all of which should be washed down with beer (Nils Oscar is the local brewery) and the hotel's own delicious akvavit, a smooth but lethalfirewater flavoured with caraway, fennel and aniseed. It was delicious. I was replete. If truth be told, all I wanted was to be alone.
Grand Hotel (00 46 8679 3550; grandhotel.se) offers doubles from SEK3,700 (£273) per night. British Airways (0870 8509 850; ba.com), Ryanair (0871 246 0000, ryanair.com) and SAS (0870 60727 727; scandinavian.net ) fly to Stockholm. Scantours (020-7554 3530; scantours.co.uk) offers packages. The opera season runs until 9 September (dtm.se)