The moment Adjaye moved on from eccentric houses for celeb boho types and entered the public realm, he became an altogether different proposition. Of course the style glossies will always love him - for Vogue he designed a "dress" with fashion label Boudicca that turned out to be a painful asymmetric hammock of wooden sticks, for instance - but he has also done a couple of public libraries for tough old Tower Hamlets in East London. One cleverly colonises the left-over spaces of a run-down 1960s shopping mall, the other is all-new and due to open shortly. And then Adjaye started winning international competitions as well. The first fruits of what could well become a globetrotting career are now to be found in Oslo. As first overseas clients go, the name of Nobel is as blue-chip as they come.

The £14.5m Nobel Peace Centre in Norway's capital, Oslo, has the highest of ideals - to act as a permanent museum of the Nobel Peace Prize and the whole idea of individuals striving to make peace in the world. It sounds far too worthy to make much of a public attraction. And this is probably why Adjaye won the job. Because Adjaye, the great showman, can make desirable, must-see places out of anything. In this case the anything was Oslo's former Vestbanen railway station, which despite being in a run-down wharfside bit of town happens to be pretty much dead central on the map of the city, right next to City Hall.

Some architects feel uncomfortable with conversion projects but others - Norman Foster, say, and certainly Adjaye - excel at them. There's something about taking an old building and teaching it new tricks. And the moment you arrive at the old station, you know that a deft hand has been at work.

The first thing you see, set in front of the cream-stuccoed Italianate façade of the old building - is a curious perforated rectangular metal box. It is a freestanding entrance portal that you are not obliged to walk through, but which makes you want to. Its floor is steeply curved, difficult to negotiate. The perforations appear to be randomly clustered. Are these bullet holes? Look down on it from above, and all becomes clear. The holes make up a map of the world, organised by centres of conflict. Just inside the entrance of the museum proper, you pass through another version of the same idea, where the holes, if you press your ear close, tell you something of their story.

Adjaye is a romantic architect. He likes gorgeousness. Colour, texture, spectacle. The Peace Centre starts off as it means to go on- the reception and shop is intense red throughout - and no space in it goes further over the top than the shimmering gold-lined chamber of the "Passage of Honour". Display-wise, this is no more than a picture and a bit of information about the most recent Peace Prize laureate, but in Adjaye's hands it becomes a gateway to paradise. Elsewhere on the ground floor, the jungle intrudes in the intense green patterned walls of the "Café de la Paix" restaurant. That patterning looks familiar, and it is. Turner Prize winner Chris Offfili, a long-time collaborator with Adjaye, devised it.

The displays, devised by a number of artists, designers and audio-visual specialists, are of the kind which work on several levels. You can let the images and sounds wash over you, or you can stop and dig into them, in various ways, to find more information. Adjaye constructs the matrix for all this to happen in. You are taken on a snaking path through sounds and images of unspeakable acts. You find yourself in a room full of small interactive screens on stalks, each one representing a Peace Prize winner. The effect is beautiful, but the grit is there: you have to deal with Kissinger and Arafat.

The American display technologist David Small is key to the success of this, and for the amazing corner room consisting of a lectern with a "book" about Alfred Nobel. The book is physically real, but the images and information in it are electronic. As you turn the pages and touch them, they change to provide more details. It's pure Harry Potter. As you turn to the page dealing with Nobel's global travels, suddenly an opaque window in the old station turns transparent, and you are looking out across Oslo's harbour. That's impressive.

Adjaye has acted as a kind of circus ringmaster, cracking his magic whip, nurturing the illusion of being in a world apart. To compare the Nobel Peace Centre with circus, or theatre, might seem derogatory, but not so. You are not in an old station in the Nobel Peace Centre in Oslo. Fleetingly, you are somewhere magical.

David Adjaye website: www.adjaye.com
Nobel Peace Centre: www.nobelpeacecenter.org
Tim Soar, photographer: www.soargallery.co.uk