The oval spirals - one of them a building, two of them landscaped mounds - together form the latest "Maggie's Centre", one of a burgeoning chain of support centres for people affected by cancer. The idea for these friendly, useful, non-clinical places came from the eponymous Maggie Keswick, Jencks' wife, as she herself was fighting cancer in the 1990s. Ten years after she died, Maggie's Centres are a proven success. Each is different and some are extraordinary. Charles Jencks is a very rare beast indeed, a private individual whose private loss has turned him into a producer of fine architecture for the public good.

A UK-based American intellectual whose taste for cosmological musing is underpinned by a wry self-deprecation, he hob-nobs with the architects he commissions. Zaha Hadid is doing the next one, in Fife. She, plus Frank Gehry, Daniel Libeskind, Zaha Hadid and Richard Rogers are the big names Jencks has signed up through the Maggie's organisation, which is now expanding out of Scotland into London, Oxford, Cheltenham and Cambridge. The completion of Gehry's centre in Dundee in 2003 - his first British building - suddenly put the Maggie's concept on the international map. Hadid's will be her first British building. But the global names are not the whole story. The first Maggie's in 1996 was a stable building converted by Edinburgh architect Richard Murphy. This latest one in the Highlands is by Glasgow architects Page and Park, their second. You can just see them sweating blood to cut it with the international elite.

You don't often get the chance to design an upwardly-spiralling building, a mini-Guggenheim. David Page is happy to admit that Jencks allowed him into a world of larger possibilities than usual. Moreover, the two collaborated. Jencks, who has established a reputation as a land artist, did the landscape here. Those familiar with his famous "garden of cosmic speculation", designed with Maggie at Portrack House in Scotland, will recognise the hand at work here: symbolic mounds and patterns cut into the grass. In this case the metaphor being employed is of the division of cells and the way that cells exchange information with each other. Jencks also had an influence on the design of the building itself, working with Page to develop a place where architecture and landscape are all part of the same overall composition. The lenticular shape of the building, its stepped green-copper flanks, relate directly to Jencks' hillocks with their paths lazily looping up to contemplative seats on top.

It's the opposite of Gehry's effort at Dundee. That one was all about maximising the tremendous view out over the Firth of Tay. This one is so hemmed in by roads that there are no views at all to speak of. So the place becomes internalised, with its enclosed gardens and series of intriguing internal spaces. So the Jencksian hills are a bit of a perversity in that they lift you out of this zone of tranquillity into full view of the chaotic surroundings. This means they are more to look at than climb up, a glorified screening device. Nor is this the building's only contradiction.

An upwardly-spiralling shape, with the walls sloping outwards like Frank Lloyd Wright's famous Guggenheim in Manhattan, means that upstairs is logically more important than downstairs. Once you have taken in the various interconnecting meeting and sitting areas downstairs, plus the big kitchen that is at the centre of all Maggie's Centres, you want to climb the staircase with its fine stainless-steel balustrade, your gaze led by the timber-lined walls curving up and away. If you do this at Gehry's Dundee example, you find yourself in a look-out tower. Here, you just find yourself in an over-large and slightly claustrophobic upstairs office. True, there's nothing much to look out over, as we've seen. But it still feels like a missed opportunity, in a building that is all about upwards movement.

These, however, are minor cavils. What you get to see as a user of this building is excellent: the flow of it, the play of light, the sense of openness, of new possibilities. It is a friendly space, one obviously special and distinct. Which means that you, if you go there, also feel special and distinct. You are anything but part of a production-line health system. It's casual, domestic, there are no uniforms or medical equipment. Instead, you do all the talking and advice-taking and fact-finding that you can never get in the pressurised world of a big hospital. Which means you feel more in control of what's happening to you.

Page talks about the remarkable difference that outward-canting walls make: this feels a much bigger place than it really is. Architecturally it is striving for importance, and that is right: it is an important place that just happens to be small. Now that Maggie's Centres are rolling out nationally, we can see something remarkable happening. Architecture can certainly reassure, and uplift. Just sometimes, perhaps, it can help to heal as well.

www.maggiescentres.com - what the organisation is about.
www.charlesjencks.com - the maestro of architectural mystery
www.pagepark.co.uk - find out about its architects.