The Millennium Dome has opened to welcome its first paying guests, as the nation recovers from celebrating the new millennium.

After a spectacular night of revelry, the Dome spent the first hours of 2000 in apparent pandemonium as scores of workmen dismantled the huge performance stage and erected a new one.

The visitors were the first to see the new Rest and Body Zones, whose exhibits include a huge model of a beating heart.

Despite the hangovers, up to one million people watched a huge millennium parade through the centre of London with 12,000 performers.

About 6,500 Americans were among those who flew to London from all over the world for the festivities - one of the largest peace-time airlifts of Americans ever into the UK.

A procession through the city is a New Year tradition, but this time, it was bigger than ever.

Prime Minister Tony Blair praised the peaceful way the festivities had passed off.

He said the police had done a "fantastic job" in making sure millions of people enjoyed themselves.

He added: "What struck me both last night and again today is this real sense of confidence and optimism. You just want to bottle it and keep it."

Westminster City Council reported that road sweepers swept up more than 150 tons of rubbish left by three million revellers in central London, who witnessed huge firework displays over the River Thames as Big Ben chimed midnight. Fifteen percent of the refuse comprised champagne bottles.

The UK's celebrations included the Queen and Mr Blair among a crowd of 10,000 people at the Dome, addressed by the Archbishop of Canterbury, Dr George Carey.

The Queen had earlier lit the National Millennium Beacon, triggering a string of 10,000 beacons across the UK.

But the much-heralded "River of Fire" pyrotechnic display was seen by some revellers as a damp squib. A spokesman for Big Time, the company which organised the display, said it worked entirely as planned.

There were huge street parties across the rest of the country including Cardiff, Edinburgh, Belfast, Manchester, Birmingham, Plymouth and Londonderry.

So far, there are few signs of the dreaded millennium bug, which it was feared would cause chaos as computers failed to recognise the date 2000 and shut down.

The first dawn of the millennium reached the UK at its most easterly town - Lowestoft in Suffolk- at 0804 GMT.

Crowds thronged the promenade and beaches with some people even taking a celebratory dip in the North Sea.

Alison Webb, 28, from Birmingham, and Monstrat Abomide, 29, from London, both claimed the first baby of the millennium by delivering a girl 15 seconds after midnight.

At the other end of the age range, Ellen Watson, of Staines, Middlesex, is celebrating her 100th birthday with the arrival of the new millennium.

A record 18 people are celebrating the millennium in style after they were made millionaires in The National Lottery's special Big Draw 2000.

The previous record for creating a batch of overnight millionaires was 14, set by a double rollover draw in 1996.