London 2012 Festival: An Olympian feat?

The London 2012 Festival launches on 21 June. The 12-week Festival is billed as an "explosion of arts and creativity" that runs alongside the London 2012 Olympics.

This Q&A asks why it's happening and looks at what's coming up.

The London 2012 Festival is the grand finale of the Cultural Olympiad, a programme of arts events that have been running since 2008.

The nationwide festival begins on 21 June and runs through to 9 September - the end of the Paralympic Games.

No, while there are many events taking place in London, the festival programme features events across the UK.

For example, Deborah Warner's outdoor installation Peace Camp, will see eight glowing encampments appear simultaneously in remote coastal locations, from County Antrim to the tip of Cornwall, from the Isle of Lewis to the Sussex cliffs.

The list goes from Alan Ayckbourn to Jay-Z.

Among the well-known artists taking part are Damon Albarn, Daniel Barenboim, Cate Blanchett, Gustavo Dudamel, Tracey Emin, Stephen Fry, Antony Hegarty, Damien Hirst, Zakir Hussain, Anish Kapoor, Mike Leigh, Baaba Maal, Tim Minchin, The Noisettes, Yoko Ono, Simon Rattle, Rihanna, Scissor Sisters, Wallace and Gromit, Doctor Who, Julie Walters and Ai Wei Wei.

According to the organisers, the Festival involves 25,000 artists from all 204 competing Olympic nations in 12,000 events and performances at 900 venues all over the UK.

The programme includes 137 world premieres and 85 UK premieres.

The Festival opens with five headline events.

In Wales, artist Jeremy Deller's life-size inflatable replica of Stonehenge, entitled Sacrilege, will "pop up" at the National Botanical Gardens in Carmarthen.

In Scotland, an open-air concert set against the backdrop of Stirling Castle will be led by superstar conductor Gustavo Dudamel and the Simon Bolivar Symphony Orchestra of Venezuela who are joined by The Big Noise children from Rapploch.

In Northern Ireland, Londonderry hosts a Peace One Day concert with Pixie Lott, Imelda May, Newton Faulkner, Guillemots and Wonder Villains.

In England, the City of Birmingham Symphony Orchestra will present the UK premiere of Weltethos, an epic choral work by Jonathan Harvey.

On the same night French street arts company, Les Commandos Percu, will light up the shores of Windermere in Cumbria with a pyrotechnic show.

Other events include the unveiling of Yoko Ono's IMAGINE PEACE art installation on London 2012 Live Site screens at outdoor venues throughout the UK.

Australian comedian and musician Tim Minchin performs at The Eden Project near St Austell in Cornwall.

There will be the world premiere of Crow, a production based on Ted Hughes' Crow poems, by Handspring Puppet Company UK.

BBC Radio 1's Hackney Weekend will feature more than 100 acts including Jay-Z, Rihanna, Florence + the Machine, and Jessie J.

Yes, there are events showcasing performers and artists from all 204 nations.

These include the BT River of Music on the Thames, the Poetry Parnassus at the Southbank Centre, and The World in London - 204 photographic portraits of Londoners, each originating from one of the countries participating in the Games.

Royal Opera House executive Tony Hall has been the chairman of the Cultural Olympiad Board since 2009, with Ruth Mackenzie as Festival director from 2010.

"When the UK won the bid for the Olympics in 2005, we promised to return to Baron Pierre de Coubertin's original idea of an Olympic Games based on the three pillars of sport, art and education." - Ruth Mackenzie

"With 10 million opportunities to take part in events across the UK for free, this is a festival that everyone can enjoy, try something new and experience art from around the world as part of the Olympic and Paralympic Games celebrations." - Tony Hall

Organisers are keen to point out there are 10 million free opportunities to take part in the festival.

These include events like the Hackney Weekend (100,000 free tickets) and the Peace One Day concert in Londonderry.

Two days before London 2012 Festival began, organisers revealed that about half of the event's 4m paid-for tickets have been sold.

Another 2.3m free tickets, out of a total 10m, have been snapped up.

There is a comprehensive list of highlights in this article and you can dig deeper into the schedule on the official London 2012 Festival website .

The BBC's coverage of the festival will be under the spotlight in a special section of its Olympics website .

Yes, some are already over. The Globe to Globe season - in which all 37 of Shakespeare's plays were performed in 37 different languages at Shakespeare's Globe, was officially part of the Festival and finished in early June.

Dance season Tanztheater Wuppertal Pina Bausch: World Cities 2012 has started, as has Elevator Repair Service's epic eight-hour production Gatz, a word-for-word staging of Scott Fitzgerald's The Great Gatsby.

Where to start?

The Adain Avion project will see a wingless DC-9 aeroplane transformed into a mobile arts space tour around Wales (24 June - 14 July)

A string quartet will play live from four helicopters above Birmingham for the world premiere of Stockhausen opera Mittwoch aus Licht (22 - 25 August)

An artwork inspired by the final scene of The Italian Job will see a full-sized replica coach balanced on the De La Warr pavilion in Bexhill-on-Sea.

And Monty Python star Terry Jones and Anne Dudley have created a new children's opera The Owl and the Pussycat that will travel through London's canals.

Principal Funders of the Cultural Olympiad and London 2012 Festival are Arts Council England, Legacy Trust UK and the Olympic Lottery Distributor, which is investing £16.6m to support the Cultural Olympiad.

The festival has an overall investment of £55m.

Director Ruth Mackenzie says: "Some of you might think it's a lot, but I assure you, for a 12-week festival over the entire United Kingdom... [it] is a pretty small investment and I hope that when we do the final figures after the festival we are able to demonstrate pretty good value for money."

Scottish choreographer Michael Clark has been commissioned to create a large-scale, participatory dance event at Glasgow music venue Barrowlands to mark the handover to the Glasgow 2014 Commonwealth Games.

After that Ruth Mackenzie and her team will begin the process of assessing how it all went. It's expected to take several weeks.