The alfresco approach was adopted because there is "no museum and gallery infrastructure in the town", says curator Andrea Schlieker. "The solution was to put art on people's doorsteps."
There is a museum in Folkestone that the triennial's organisers could have hooked up with, but it is currently closed owing to damage inflicted by the recent earth tremors felt across the county. It is housed in the local library and is to reopen soon as a history resource centre.
A spokeswoman for the museum says it's a "dreadful shame" that they couldn't use the triennial to promote the museum and its collection, though the adjoining council-funded Sassoon Gallery is showing a film by Tacita Dean.
And the triennial will have a longer-term impact on the town's cultural provision, as at least eight sculptures will be permanently sited in Folkestone once it ends.
The triennial also forms a major part of an arts-led regeneration of the area that is being spearheaded by the Creative Foundation (an organisation founded by local businessman Roger de Haan, former chairman of the Saga Group, which provides services for the over-50s).
As well as the triennial, there is a masterplan for the harbour and seafront, and plans to create a £38m City Academy specialising in the arts, a performing arts centre and a creative quarter for artists. The Creative Foundation is also relocating the Metropole Galleries, a contemporary art space it runs in the town's centre.
Funding for the triennial is coming from a variety of sources, including the Creative Foundation, Kent County Council and Arts Council England. The overall aim is to make Folkestone a major place for contemporary art following the demise of its fishing and tourism industries.
"Folkestone could become a regional centre of excellence for international contemporary art, like Glastonbury and Glyndebourne for music or Hay-on-Wye for literature," Schlieker says.
Along the same stretch of coast is Margate, which has just celebrated its less ambitious, 10-day Margate Rocks contemporary art festival. According to Thanet District Council, it is one of the best weeks in the year for local businesses and the council is keen to use the event to help boost the town's commercial profile and counteract its media-driven "wild west" image.
Museums here are more integrated into the festival programme; artists Sarah Craske and Stacy Keeler worked closely with Margate Museum, drawing on its archives for their Women's Land Army project.
In 2010 the long-awaited £17.4m Turner Contemporary gallery opens on the seafront in Margate; until then it has a space on the town's high street. It has recently commissioned the sound element for Celestial Radio, a radio station broadcasting from a crystal ship built by artists Zoë Walker and Neil Bromwich.
The boat will dock at Folkestone and nearby Whitstable, which is soon to launch its own biennial (21 June-6 July). John Haywood, marketing director at Turner Contemporary, says the festival allows the gallery to access "established and emerging" audiences.
So can biennials attract people from outside a host city, enabling it to tap into new audiences? Ben Harman, curator of contemporary art at Glasgow's Gallery of Modern Art (GoMA), thinks so.
He points out that GoMA's current Jim Lambie show, part of the city's four-year-old Gi festival of contemporary visual art, is pushing visitor figures to 2,500 a day compared with the usual average of 2,000. More than 1,700 people turned up on the opening night of the show. "An art crowd is showing up, as well as our regular visitors," Harman says.
Reyahn King, the director of art galleries at National Museums Liverpool, is just as optimistic about the forthcoming Liverpool Biennial: "Because it happens out there in the streets, as well as in our venues, I think it should in time generate new audiences. Similarly, with each year it grows stronger and more likely to attract tourists."
The Merseyside festival can lay claim to the title of the UK's first biennial of international contemporary art. Its chief executive Lewis Biggs points out that there have been forerunners to the event, such as Artranspennine 98 and the British International Print Biennale in Bradford, both of which are now defunct.
Artranspennine 98 consisted of more than 40 projects involving 60 artists throughout the Pennine region financed mainly by the Heritage Lottery Fund. It never developed into a five-yearly show as planned because of organisational and funding changes.
But Biggs, who was co-curator of the 1998 show, also says the Liverpool Biennial continued some of the impetus of Artranspennine. The Liverpool Biennial of Contemporary Art charity was founded in 1998 and launched its first biennial in 1999.
Biggs says this was "the UK's first exhibition of this scale and ambition". The 1999 event attracted 190,000 visitors and this year 500,000 are expected.
In Liverpool, as with other major biennials worldwide, a portion of work on view has been specially commissioned for the event. Artists and their dealers often reclaim these pieces, but host cities are tentatively brokering agreements so local museums and galleries can acquire the new biennial art. Biggs is in discussions about a potential Walker Gallery commission from the Biennial's international exhibition.
The plan is to develop a "collectors' circle", with the long-term aim of enabling international artwork commissioned by the biennial to enter the Walker's collection, with backing from Arts Council England and the Contemporary Art Society (CAS). GoMA is also planning to purchase a Jim Lambie work from its current show.
Buying art from biennials could go some way in filling the gaps in contemporary art collecting by regional museums, says Sheila McGregor, chairwoman of the Sheffield Contemporary Art Forum (the not-for-profit company behind the Art Sheffield 08 festival).
"Renaissance in the Regions has done many excellent things, but it has not revitalised contemporary art collecting," McGregor says. "To remain knowledgeable about new developments, you need to travel - to London and other international centres. Curators in the regions don't have those opportunities, especially since the disbandment of the Special Collection Scheme in 2005."
The £3.3m scheme was run by the CAS and allowed the 15 museums and galleries involved to travel, research and acquire a wide range of art. The CAS still organises trips to biennials in the UK and abroad through its professional development programme, but at a cost; a year's subscription to the programme is £195.
Harman at GoMA agrees that attending key foreign festivals, an integral way of improving curatorial practice, is difficult. "There is a lack of understanding that curators need to travel," he says. "Some struggle to get away from their desks."
Funding from Culture and Sport Glasgow, the trust that manages Glasgow Museums, has allowed him to go abroad, but the consensus among regional curators is that it is increasingly difficult to persuade local authorities to fund these overseas visits.
Despite these problems, the major international biennials are still important research venues for curators and festival organisers in the UK. Harman singles out the Venice Biennale as an essential place to spot contemporary art trends.
UK galleries are also using the Italian event as a commercial and curatorial platform; in 2005, Birmingham's Ikon Gallery organised an exhibition of three works by British artist Grace Ndiritu in Venice.
But some UK festival organisers shy away from the blockbusting international model. "We did not want to copy other biennials, which are all about passive celebrity curators, with exhibitions just planted in venues," says Alnoor Mitha, director of the Asia Art Triennial in Manchester. Mitha prefers to bring galleries together under one umbrella, which he believes gives curators a "sense of ownership".
The advantages of collective enterprise are reiterated by the organisers of Art Sheffield 08 and Gi. Both are evangelical about showcasing local as well as international talent at their festivals.
"There can be a 'travelling circus' element to biennales, with a limited range of big name artists appearing at all of them," says Mark O'Neill, head of arts and mu-seums in Glasgow. "Gi aims to attract the best international artists, but it is rooted in the local visual arts community."
Gareth Harris is a freelance arts journalist
Venice Biennale
2009
The world's leading art biennial was founded in 1895 as the International Art Exhibition of the City of Venice. Artists from 76 countries were represented at the 52nd International Art Exhibition in 2007, which attracted nearly 320,000 visitors. Next year's biennale is being curated by the critic Daniel Birnbaum, co-curator of the 2005 Moscow biennial.
www.labiennale.org
Sydney Biennale
18 June-7 September 2008
The 16th Sydney Biennale boasts a special online venue, which will feature artists' projects.
www.bos2008.com
Sao Paulo Biennial
26 October-6 December 2008
This year's edition of the second oldest biennial in the world, founded in 1951, will include live performances - but the second floor of the biennial pavilion, designed by architect Oscar Niemeyer, will be left completely empty.
bienalsaopaulo.globo.com
Documenta
9 June-16 September 2012
The quinquennial grande dame of art festivals held in the German town of Kassel was launched in 1955 in an attempt to reconcile postwar Germany with modernity.
www.documenta.de
Sculpture Projects Münster
2017
The northwestern German city of Münster hosts this 10-yearly contemporary sculpture exhibition. Artists represented in 2007 included Jeremy Deller and Mark Wallinger. More than 35 works from the previous four editions, the first of which was in 1977, are dotted around the city's streets.
www.lwl.org/LWL/Kultur/skulptur-projekte/information
Folkestone Triennial
14 June-14 September 2008
Twenty-two artists, including Tracey Emin, have been commissioned to make public sculptures for the inaugural triennial, which is based on Sculpture Projects Münster.
www.folkestonetriennial.org.uk
Liverpool Biennial
20 September-30 November 2008
Highlights of the fifth Liverpool Biennial include Chinese artist Ai Weiwei's Web of Light, an installation of crystalline strands which will stretch across the Albert Dock.
www.biennial.com
Contemporary Art Norwich
11 July-22 August 2009
The 2007 edition of this biennial commissioned the German artist Karsten Bott to create a museum within a museum at the Norwich Castle Museum and Art Gallery. The Sainsbury Centre for Visual Arts was also involved in the event.
www.contemporaryartnorwich.co.uk
Glasgow International Festival of Contemporary Visual Art
2010
The Gi Festival aims to provide a platform for contemporary and newly commissioned art.
www.glasgowinternational.org