Art Nouvel.

In east Berlin, a new development of shops, offices and apartments by Jean Nouvel brings a very Gallic form of glamour to one of the main thoroughfares.

Berlin, both united and torn apart, is peculiarly eloquent of history and the anguish of division. It is a city of echoes. They reverberate down the years as you look over the vast plain under construction that is the Potsdamer Platz in east Berlin - at the beginning of the century one of the liveliest squares in Europe - or glimpse the revolt in graffitti covering a fragment of Wall, or tread no-man's-land in the company of ghosts at Checkpoint Charlie. Preserved in literature and film, the old border post is marked by a lone guard tower and has been declared a historic monument.

Poignancy always accompanies the dismantling of buildings and place, and Berlin which is at the moment the biggest building site in Europe is infused by it and inevitably is in something of a vacuum. So it seems significant that the architect of a new building nearing completion in its eastern part has chosen to weave a narrative around voids.

The cones of empty space penetrating Jean Nouvel's department store in Friedrichstrasse are dramatic, but have more to do with the architect's play on the dematerialisation of the solid, 'to touch the infinite' - and with his interest in surface and texture as means of communication. Friedrichstrasse is Berlin's answer to the Fifth Avenue, and the building is in a prominent position, standing where the long street crosses the Franzosische Strasse. Containing the Galeries Lafayette and other shops, as well as offices and flats, it rises in transparent silvery tiers articulated in silkscreened glass and steel and turns the corner like the prow of some great vessel. From the street, the shapely transparent skin gives the passing motorist glimpses of the interior, of luminous cones apparently suspended in space.

But the main spectacle is in the middle, dazzling the neighbourhood and drawing people to it like a magnet. On the ground floor, which has been conceived as an internal plaza continuing the street outside, the Galeries Lafayette and ancillary shops revolve around an enormous vortex - two cones of empty space set base to base, spun up to the light and down into subterranean depths. Lined with curved partly reflective silvered glass, the cones scintillate with coloured light and flash refracted images caught from the spaces that surround them.

Nouvel's play on transparency and opacity, his interest in using light to shape space and his games with perspective have been worked out in previous schemes, particularly in his crystalline design of the Cartier Foundation on Boulevard Raspail in Paris. Such buildings impinge lightly upon the urban context. In Berlin, Nouvel's insertion seems a particularly Gallic show of glamour. His other preoccupation with expressive surface has been carried to literal lengths here, for the exterior of the building has been treated as an 'interface' and when completed will carry information transmitted from big screens on Friedrichstrasse and Franzosische Strasse; while screen-printed patterns cast hazy intimations of the cones within.

Fundamentally, the building is a synthesis of a modern mixed-used development and traditional Parisian department store with romantic galleries and cupolas. Viewed from above, the roof studded with the circular openings of cones and cylinders looks like an inverted colander, but the plan is a deep one and the penetrations are a means of bringing light down through the building, even to the subterranean parking levels, and at the same time provide easy ways of orienting yourself.

This is a sleek shiny building, a Gallic magpie's nest full of brightly coloured objects that must stun a public deprived for so long of such a market. And yet, standing on the ground floor and peering into the crater, as you might into the mouth of a volcano, you do feel on the edge of a dark vortex. Scale makes the view really vertiginous and Nouvel has made you conscious again of dark echoes. Checkpoint Charlie is not far away, nor is the Friedrichstrasse Bahnhof and Tranenpalast - the Palace of Tears - where departing visitors from the west once left their friends and relations. P.M.