The eyes of the world are on London as the final countdown to the start of the 2012 Olympics begins.
Doorbells, handbells and church bells rang across the country to accompany Big Ben, which rang for three minutes on Friday morning, to mark the beginning of the Games.
The bell-ringing, which began at 8.12am, was an "artwork" by Turner Prize winner Martin Creed, entitled "All The Bells" and commissioned by the London 2012 Festival.
The Olympic flame is on its last journey down the River Thames, after beginning at Richmond's Bushy Park, it travelled through the maze at Hampton Court Palace before hopping onboard the Queen's row barge Gloriana, last seen at the Diamond Jubilee.
The £1m royal barge, rowed by a crew of 16 former British Olympic rowing crews including gold medal winners James Cracknell and Jonny Searle, is passing along Richmond Riverside, Putney Embankment, Battersea Bridge, along the South Bank to Tower Bridge.
The flame will go to City Hall and continue into east London towards Stratford in time for Friday evening.
Its final destination, after an 8,000 mile journey to all corners of the nation, is the Olympic cauldron at the stadium for the opening ceremony.
The identity of the final torchbearer is a closely guarded secret.
The big stage rehearsals for Friday's £27 million opening ceremony are now complete and more than 10,000 athletes from 204 nations are preparing to compete for a coveted Olympic title.
Oscar-winning director Danny Boyle, the mastermind behind the opening ceremony, believes the curtain-raiser at the Olympic Stadium is fitting both for London and everyone who will compete at the Games.
The ceremony has been shrouded in secrecy, although some images and features have been released on Twitter, prompting many to use the hashtag #savethesurprise.
"Part of the theme of our show is that this is for everyone," he said.
"It is very easy to get it out of perspective when you are doing a warm-up act like this and we have not forgotten that perspective.
"We all know that we are a warm-up act for the 10,000 athletes who are getting ready to compete in the Olympic Games.
"They are the most important thing about the show, except one thing. This is a show that has been built out of our volunteers. They are the people who have turned up in rain and terrible conditions and have built this show.
"They really are the most extraordinary group of people. This show is theirs. This country is theirs. They really are the best. They really are the best of us."
Special effects, big names and bags of enthusiasm will be used to help celebrate the best of British in front of an audience of more than 70,000 who will be watching live at the stadium in Stratford, east London.
Millions more globally are expected to tune in on television but many competitors will be missing from the long and late-starting athletes parade.
Competition clashes or just preferring to rest instead as part of vital preparations mean that British swimmers, athletes, track cyclists and rowers will skip the ceremony.
Team GB has previously estimated about half of the 541-strong team will not attend, meaning major stars such as Jessica Ennis, Victoria Pendleton and Mo Farah may not parade at the climax of the big budget extravaganza.
The build-up to the Opening Ceremony has seen many put aside any cynicism or criticisms about the next fortnight.
Prime minister David Cameron, after seeing previews of the show, predicted the public should expect some "spine-tingling" moments.
He said: "There are one or two moments I think are really spine-tingly and I certainly have been very moved by them.
"We have a lot to celebrate as a country and I am sure we will do a great job."
The show is set to feature aspects of Britain's past, future and contribution to culture, lifestyle, technology and music.
He said: "I would have thought the difficulty is how do you cram in all that is great about our country."
Dancing nurses, the biggest ringing bell in Europe inscribed with lines from Shakespeare, and children will be key features of the opening ceremony.
There are 15,000 square metres of staging - equivalent to 12 Olympic-sized swimming pools.
A flying system that can lift 25 tonnes - the same as five elephants - is used.
There will be 12,956 props, which is more than 100 times more than used in a West End musical.
The event also boasts a million-watt PA system using more than 500 speakers and 50 tonnes of associated sound gear.
This is double the amount of speakers than on the main stage at Glastonbury.
The identity of the person who lights the flame will remain secret up until the final moment, but some of Britain's greatest Olympians will take part in the closing stages of the ceremony.
These will include five-time Olympic rowing champion Sir Steve Redgrave and double Olympic decathlon gold medallist Daley Thompson. Neither are expected to light the cauldron.
At least one bookmaker stopped taking bets on Sir Roger Bannister, the first man to break the four-minute mile, but it may be that the honour is shared between a legendary sporting figure and someone else who is symbolic of London's ambition to inspire an international generation of youth.
Footballer David Beckham, who was a key figure in the bid team that secured the Games in 2005, said the thought of tonight's spectacle gave him "goosebumps".
Writing in The Sun, he added: "I have been lucky enough to have been involved in some amazing sporting moments in my career, but nothing can compare with what is about to take place in London.
"I know every part of the Games is going to be spectacular and tonight is the night it all kicks off, with the whole world watching Great Britain and the opening ceremony.
"It will be one of those moments people will always remember watching."
The sportsman, who has revealed he has a part in the opening ceremony, continued: "I know I am biased but, what the rest of the world will see, I don't think any other country in the world could do it better."