GRAND CANARY.

The pinnacle of London Underground's achievement in extending the Jubilee Line is the largest and grandest station serving a fast developing business centre at Canary Wharf.

Of all the millennial projects, the extension of the London Underground, under the direction of Roland Paoletti, is one of the most admirable.

After the squalor and chaos of most parts of the London tube, the new jubilee Line is a haven of physical and visual order, and to disembark at Westminster, Southwark, Canary Wharf or North Greenwich is a positive pleasure. Paoletti, who appears to have been a strong client with a clear vision, has shown what can be done. (So far advertising is absent and it is interesting to find that you do not miss it. On the contrary, without distraction, you can appreciate the drama of space, raw textures and elemental form).

Canary Wharf by Foster and Partners is the grandest and the biggest of the new stations -- measuring 31 3m in length, it is apparently as long as Canary Wharf Tower is high. Its scale and the capacity to handle up to 100 000 passengers at peak periods is in response to the growing importance of Canary Wharf as a business and commercial centre.

The station is entirely underground, built of concrete within the drained West India Dock by means of cut and cover construction. In this case, the cover is a new park, with entrances to the station indicated by three curved steel and glass canopies. Ellipsoidal on plan (the ellipse is the late twentieth-century shape) they are reminiscent of Fosteritos, the affectionately named entrances to the Bilbao metro. Here, as there, the structures prevent weather entering the station while admitting light deep into the station cavity.

Paoletti's guiding principles enshrined in the briefs for each station included the need for comprehensible public space, clearly defined passenger routes and abundant escalators. Given the expected volume of traffic at Canary Wharf, the problem of circulation was of importance in design of the station and Fosters have dealt with it brilliantly. Dramatic, functional and elegantly resolved, the building has been planned with clear hard logic so that passage at all times is straightforward and there is hardly need for directions.

A kind of futuristic excitement is attached to a journey through this station. Great banks of escalators, bathed in light, carry passengers down from the Fosteritos on the surface to the ticket hall. This cathedral-like volume is articulated by a central row of colossal elliptical columns that rise, from the platform level below, to the roof, to meet the rhythmic pattern of arching ribs. (They are crowned by elliptical bearings which allow the building to move in response to geological pressures.) Naturally lit and lined down its sides by ticket machines, offices and shops, the concourse is open through its length and breadth.

More banks of escalators take you down to the platforms in the bowels of the building, 27m below ground. Apart from scale, the excitement of this station consists in the tension between the sheer elegance of the structure and the rough vigour of raw concrete. At platform level, where concrete diaphragm walls cast into the ground have been left exposed, the robust engineering aesthetic is at its most pronounced. Use of stainless steel, aluminium and glass create polished counterpoints in the composition.

To prevent vandalism and damage, the bases of columns are clad in stainless steel. As on the other new stations, glass screens along the edge of platforms protect passengers from incoming and departing trains; and as well as looking good, glass lifts improve security and deter vandalism.