From the drab ring road around Bern, the three grey steel arches poking above the hedgerows could be anything from a new shopping centre to the Swiss air force's latest hangars.
What the unpromising exterior actually contains is Switzerland's new SFr110m (£48m) Paul Klee centre, designed by the Italian architect Renzo Piano as a focal point for study of the semi-abstract artist's life and works.
Klee, born in Bern in 1879 but educated in Germany, was a founder of the Bauhaus, where he headed, successively, the bookbinding, glass and weaving workshops. His own output was as eclectic. Torn between music and painting, he chose the latter, producing drawings, watercolours and oils that vary enormously in style between periods, and even within them. Most stand out for a strong sense of colour, the result of a stylistic upheaval that followed a seminal trip to Tunisia in 1914.
But Klee's time at the top of German art proved short-lived. Soon after taking a professorship in Düsseldorf in 1931, he, like many contemporaries, was marked down by the Nazis as "degenerate". Unemployed and unwelcome in Germany, he sought refuge back in Switzerland. Although he was granted residence in Bern, the fact that only his mother was Swiss - his father was German - meant his application for citizenship was not granted by the time of his death, in pain and relative penury, seven years after his return in 1933.
Now, Bern has decided belatedly to honour one of its most famous sons. In the same year that Albert Einstein's former flat in the city centre has undergone a lavish restoration, Klee has been honoured with a new museum all to himself.
Piano's distinctive steel- spanned building comprises three distinct sections. Each has the same wide, curving steel beams, elegantly sloping glass roof and light wooden floors. Each burrows deep into the hillside on which the centre is built, masking the building's true dimensions and implying an organic structure emerging from the surrounding earth.
While the overall concept has a stylistic unity, the three sections, which Piano calls "hills", have very different functions. The middle "hill" houses the traditional museum, showing selections of Klee's works in a flexible white space, complemented by a smaller temporary exhibition area downstairs. The works will rotate regularly, says Christine Hopfengart, assistant head of the collection, allowing visitors to see far more of the 4,000 odd Klees in its collection - some 40 per cent of the total - than ever before.
Beside the central "hill", a slightly smaller section holds the centre's administrative and research core, along with seminar rooms. Finally, the third, and widest, of the three spans contains a flexible meeting hall on its main level, as wellas a 300-seat concert halland theatre underground for performances by resident companies.
Linking the three arches is a 150m-long transverse corridor, called "Museum Street" by Piano, which provides the centre's main public space for cultural information, a shop and ticket desk, as well as a cafeteria.
The corridor, accessible without an entrance ticket and open longer than the museum itself, is intended as an attraction in its own right. It also provides access to the centre's children's art museum - in deference to Klee's passion for teaching - comprising workshops designed for anything from graduate lectures to children's painting parties.
If the location and the architecture sound unusual, their idiosyncrasies have much to do with the conditions behind the centre's birth. A Klee foundation dated back to the 1950s, and Bern's municipal gallery already held a large collection, supplemented by commitments from Klee's daughter-in-law and grandson to give or lend more.
But the heirs wanted a distinct gallery. Initial ideas included extending the existing Kunstmuseum or building an annex. Financing aside, the task would have been very tricky, given the lack of suitable sites in the Swiss capital's almost unscathed medieval core.
Enter Maurice Müller, an 86-year-old retired orthopaedic surgeon, who made a fortune pioneering the replacement hip. Although no great art collector - and self-confessedly weak on Klee - he had observed both the stream of visitors to Bern over the years drawn by the artist's works and the lack of a suitable showcase.
Keen to repay the city that funded his studies, Dr Müller stumped up SFr60m for a new gallery - subject to three provisions. First, Piano, a personal friend, should design the building. Second, the centre had to be sited on land owned by the Müllers outside town. (By happy coincidence, Klee's grave is less than 100m away.) And last, the donors wanted the centre to be as interdisciplinary as Klee himself.
The conditions largely dictated the design. Rather than be put off by the traffic roaring outside, Piano used the gently curving motorway as a defining feature, dictating the slight angle of the centre's façade. Instead of turning the building's back to the swirling traffic, Piano, whose interest in curved forms is reflected in buildings from Osaka's airport to Rome's new Parcodella Musica, argued that architects had to face up to such realities, and not ignore them.
Other environmental considerations played a part too. "We conceived the idea of three hills as reference to the landscape [and] also because the undulating forms create a softer relationship between the building and the ground, between the built and the unbuilt," Piano said at the centre's opening. "Once the garden has grown the steel framework will disappear into the earth."
In spite of its odd site and style, the centre has been a hit. More than 60,000 paying visitors have come so far, excluding the countless others who have just wandered around Museum Street, says Andreas Marti, the director. That is more than half the 100,000 forecast for the centre's first six months.
Marti, a former public official in the cantonal education and culture administration, is particularly proud that the project has been realised without federal government funding, an important achievement in fiercely decentralised Switzerland.
The building was financed largely by the Müller donation, along with smaller private gifts and SFr18m from the cantonal lottery. The city and canton of Bern, along with some neighbouring communities, will stump up the annual SFr8.5m running costs.
Admirably, in non-ideological Switzerland, where arts funding is more pragmatic than neighbouring Germany, the centre is also expected to make money on its own. Marti says its meeting rooms are available to private or corporate clients and not just academics, allowing the centre to raise cash and increase its exposure to a wider public. Klee, keen to popularise and democratise art, would have approved.
