On the morning of May 11, 2003, a porter at the revered Kunsthistorisches Museum in Vienna reported an overnight burglary. Only one display case was shattered and one object stolen: a small gold salt cellar, valued at $US55 million but regarded in Austria as irreplaceable, priceless.

The Saliera was regarded as "the Mona Lisa of sculpture", a work of exquisite artistry presented to King Francis I of France by the Florentine master Benvenuto Cellini in 1543, passed to Archduke Ferdinand II of Tyrol and held in the Habsburg imperial collection in Vienna. The royal salt pot fashioned in gold and enamel depicted reclining male and female figures and mythical beasts, intended as an allegory of the Earth.

The thieves had climbed scaffolding, smashed a first-floor window, shattered the display case and left with the masterpiece, despite alarms sounding and the presence of motion detectors and video cameras. The heist sparked a national scandal and a police investigation notable for two ransom attempts, spectacular plot twists and, finally, a text-message mistake.

Nearly three years later, on January 21, 2006, a 50-year-old security-alarm specialist with no criminal record or financial problems led police to woods about 80 kilometres north-east of Vienna, where he had buried the sculpture inside a lead box. For most of the time, however, the box sat beneath the bed in his Vienna apartment. The Saliera was reunited with a small trident the thief had removed and hidden during a failed ransom and, remarkably, the sculpture sustained only a few scratches in its 1000-day absence.

As the most famous work held in the vast imperial collection of the Kunstkammer Vienna, the Saliera's next appearance in the headlines will be as the centrepiece of the museum's eagerly awaited reopening on March 1 next year, 10 years after it closed for remodelling and expansion. "This will be the culmination of a decade's work and many millions of euros," says Sabine Haag, the director-general of the Kunsthistorisches Museum, where the Kunstkammer is housed. The project will cost €18.5 billion ($17.9 billion), a combination of state funds and an innovative sponsorship campaign featuring gold bicycle helmets. Haag looks a little weary, but resolute. "It's the most important collection of its kind in the world. It will again be a true place of wonder."

Also known as a "cabinet of curiosities" and "chamber of art and wonders", the English translation of the German term Kunstkammer - "art room" - doesn't begin to describe the magnitude or magnificence of the collections amassed by the Habsburgs during 650 years of obsessive, ambitious commissioning and acquisition with limitless budgets.

It began in the late Middle Ages when Duke Rudolf IV (1339-65) founded a Habsburg family treasury of jewellery, coins, gold and silver. Successive emperors and princes added relics, documents, curios and rare objects and began commissioning works by the finest artists of the time. By the Renaissance and Baroque eras, the kunstkammers of European royalty had expanded dramatically and were regarded as encyclopaedic collections "reflecting the cosmic order of the universe and all contemporary knowledge", Haag says. Exquisite sculptures sat beside automatons, relics and bronzes beside clocks and bizarre objects fashioned from precious metal and stones. Rare natural curiosities piled up - ostrich eggs, coral, teeth, ivory (Haag is an ivory specialist) - and foreign exotica was acquired, from magical South American bezoar stones to rhino-horn goblets.

Of 8000 objects, 2200 collected by the most important Habsburg archdukes and emperors of the 16th and 17th centuries will be displayed in the Kunstkammer's 20 new rooms spanning 2700 square metres, behind a splendid portal at the entrance of the museum.

I take a closer look at the reliefs above this carved portico by torchlight late that night. I confess I feel like a burglar. "You can see so much more when you're focused on the detail, without the distractions of the day," our night guide, Marcus, whispers. His words bounce off marble and soar into the silent void beneath the splendid, richly painted cupola. The museum's night tours have the deliciously clandestine air of Ben Stiller's adventures in Night at the Museum; in the dark, you imagine Emperor Franz Josef and Sisi, his empress, might excuse themselves from their painted pageantry and descend the royal staircase.

As we ascend, Marcus points out fascinating historical connections between torchlit figures above us, and describes the tiny chip of marble missing from Antonio Canova's centrally mounted masterpiece, Theseus Fighting the Centaur, commissioned by Napoleon and damaged when it was moved here by royal decree in 1891, when a coach collapsed under its weight.

We continue creeping higher, until an unmarked door opens and we're walking on a gantry circuit on the roof. From this Baroque apogee of imperial ambition, the city of Vienna shines below like the royal treasury - rich, rare and beautiful.

FAST FACTS

Getting there Emirates has a fare to Vienna from Sydney and Melbourne for about $2075 low-season return, including tax. Fly to Dubai (about 14hr), then to Vienna (5hr 30min); see emirates.com.

Viewing there The Kunsthistorisches Museum (KHM) on Maria Theresien-Platz is in the heart of Vienna, literally and psychologically. The grand baroque building houses world-class collections of Egyptian, Greek and Roman antiquities, a roll-call of European masters (the Bruegel room is stunning) and one of the most beautiful cafes in Europe, beneath the museum's ornate cupola. Open daily except Mondays, 10am-6pm, and Thursday, 10am-9pm. Entry costs €12 (about $15) for adults, free for under-19s. Great value for travellers planning multiple visits to the KHM collections across Vienna are yearly tickets for €29. The Kunstkammer, inside the main entrance of the KHM, opens to the public on March 1 next year; see khm.at.

Guided night tours of the KHM can be arranged for groups by booking in advance; email event@khm.at.

Staying there In a brilliant 1st-district location around the corner from St Stephen's Cathedral, the boutique Hotel Topazz is strikingly modern, with oval "portholes" in a tiled corner facade and 31 well-designed rooms with clever, custom-made furnishings and the relaxed elegance of a Viennese salon. Opened in April, it is billed as the city's only green boutique hotel. Breakfast of locally sourced produce is a highlight. Rooms from €189, see hoteltopazz.com.

Helen Anderson travelled courtesy of the Austrian National Tourist Office and Emirates.