IAN COLLINS Architecture is the art that’s all around us – and the reason London has never looked livelier or lovelier than it does today. Ian Collins welcomes a festival of towering creativity as a taster to capital treasures.

IAN COLLINS

If you're off to London today, and heading for the vicinity of the no-longer-wobbly Millennium Bridge, please take care not to be trodden underhoof.

For in a re-enactment of an ancient tradition last seen barely a century ago, a flock of 60 Herdwick sheep will be herded between the markets of Borough and Smithfield to herald the 2006 London Architecture Biennale across this spectacular swathe of urban sprawl.

A droving right still theoretically bestowed on Freemen of the City of London will be revived to launch a nine-day festival in celebration of the built environment. Thousands of events up and down the country will be focused most forcefully in our cosmopolitan capital which is now one of the world's great architectural achievements.

As the flock climbs St Peter's Hill towards St Paul's Cathedral, a Salvation Army brass band will play The Lord is My Shepherd outside the organisation's glorious new HQ. (I've already sung the praises of the café on a London Link page.)

Rounding the Wren dome, the sheep will pass through Temple Bar and into Paternoster Square where they will meet their equivalent in bronze, courtesy of a marvellous monument by the late great East Anglian sculptor Elisabeth Frink.

They will then be penned at Smithfield for a re-creation of St Bartholomew's Fair, the historic market and jolly jamboree which was finally banned in the 19th century after turning into an annual riot.

The biennale programme continues until June 25 and includes invited contributions from architects around the world. It centres on the Smithfield area, with a special walking and cycling route between King's Cross and Bankside “dotted with interventions, events and guided tours”.

Screenings, talks, tours, debates, parties, feasts, exhibitions, auctions and awards ceremonies will take place in a huge range of venues, from Tate Modern to Sadler's Wells, via Southwark Cathedral, the Barbican Centre and British Library.

Check www.londonbiennale.org.uk website for details (and for information on linked events throughout the country visit www.architectureweek.org.uk).

The gala will conclude next weekend with a Passeggiata ritual stroll involving stopping, looking, listening, drinking and eating - rather than the normal blind dash and frantic gobble and guzzle which now passes for London life.

The Italian-style promenade will begin with breakfast in Borough Market, move on to lunch at Smithfield Market, dessert at St John's Square, coffee and gelato in Exmouth Market and sundowners at St Chad's in King's Cross. In between the grazing there will be a lot of gazing at architectural highlights and exhibitions to be pointed out en route.

The five-kilometre route will be signposted in three different forms of markers - the most novel being scores of strategically-placed weather balloons, tethered at different heights to be prominent from key perspectives, particularly where there is a change of direction.

The aim is to have web cameras fixed to a fair number of these balloons, giving views over buildings that would not normally be visible at human height. Such pointers will also mimic the way architects look at structures and the immediate environment.

At eye level, there will be railings exhibitions (a Sacred Thames show curated by writer Peter Ackroyd on Millennium Bridge, for instance) and window posters.

And, thirdly, the pavement will be marked with biodegradable paint, giving details of landmark buildings in the vicinity and directional information. Visitors who fear being lost in the concrete labyrinth of the Barbican should note that the faded yellow route line has now been vividly repainted.

There will be an art installation on Clerkenwell Green and a vast London Art, Architecture and Design Show transforming the British Library piazza into a vibrant venue complete with a landscape of white inflatable pavilions.

That latter setting is particularly appropriate for Colin St John Wilson's ziggurat design was famously barracked and almost blocked by the Prince of Wales - whose self-appointed role as custodian of taste for contemporary British architecture will be the subject of a biennale debate.

The festival HQ - Smithfield House, Lindsey Street, EC1 - will host the headline exhibition Big London Brainstorm, a visually striking display of the ideas of capital-based celebrities, architects and designers in response to the 2006 Biennale theme of Change. Designs by guest festival lecturer Zaha Hadid - who has already sold out the 1162-seat Barbican auditorium for her talk on London's changing skyline - will be on view in Smithfield Gallery.

Besides tours and talks, the Barbican will be screening a film called Building the Gherkin on Norman Foster's instantly-cherished beacon building at 30 St Mary Axe (whose greatest gift to London has actually been the recent restoration of Trafalgar Square). This will be counterpointed with a reprise of The London Nobody Knows - a tour of the grim and grey capital skyline of still-recent memory.

Beyond the festival, London now offers a visual banquet for any visitor on any occasion. A trip on the Docklands Light Railway, or a cruise along the Thames from Westminster to Greenwich, will convey an array of dazzling delights (as well as some frazzling eyesores!).

In no particular order, my own Top Ten London buildings or structures are:

t St Paul's Cathedral.

t Natural History Museum.

t Sir John Soane Museum.

t St Pancras Station.

t Kenwood House.

t British Museum (with Foster's stupendous Great Court canopy).

t Bevis Marks Spanish and Portuguese Synagogue.

t Covent Garden Market.

t Albert Bridge.

t Barbican Centre.

The café in the lovely HQ of the Royal Society of British Architects, Great Portland Street, is a good coffee stop. And the new Architecture Gallery at the Victoria & Albert Museum is a great spot for putting the highs and lows of 21st century London into historical perspective.

London has been a building site for two millenniums and, from my vantage point on top of the Barbican - with a City skyline which has been transformed since the 2004 biennale - it has never looked livelier or lovelier.

Architecture is the art form which, for good or bad, affects our lives most powerfully. At last we seem to be cracking the code of how to conserve the best of the past, revive or remove flagging buildings and cope with the shock of the new to create a truly living, breathing, moving city. The 2006 London Architecture Biennale is just a taster.

www.londonbiennale.org.uk

www.architectureweek.org.uk