I expected Dome to be cheap and shoddy. But it is the most enchanting show in 1,000 years

For more than two years, we have lived and suffered through the birth pangs of this great white mushroom as it has slowly thrust itself up through the soil on the banks of Britain's greatest river.

For more than two years, we have lived and suffered through the birth pangs of this great white mushroom as it has slowly thrust itself up through the soil on the banks of Britain's greatest river.

Now the carping and moaning and bitching are finally over. The Dome and all its wonders are ready to receive us in our millions. The party to end all parties can begin.

In just 18 days' time, as the midnight hour approaches to end the bloodiest and most turbulent century in the two millennia that are coming to a close, Queen Elizabeth II will sail down the Thames to Greenwich, south-east London, by barge - just as her ancestor and namesake used to do four centuries ago to see off the battle fleets as they sailed off to start building the greatest empire in history. She will stand before thousands of the most famous icons of this, rather more modest Elizabethan era, and tell the world that Britain can still put on the biggest show on the biggest night of the century.

But can we? Will this gaudy slice of architectural gigantism, so badly mauled by so many, finally come good and capture the hearts and minds of millions? Or will it be the resounding dud that so many moaners have forecast? Is it too far away from 90 per cent of the population and too horrendously expensive for most working families? Is it just another naff theme park? Has it all been a waste of £758m?

Like most people, I had been bored and infuriated with it all. The endless bickering, the sour political nit-picking and the almost hysterical media venom that it had stirred had left a sour taste in the mouth. I had never been within a mile of the place. But the invitation to have a peek inside on Friday was irresistible, and on a sparkling winter afternoon I finally made the journey by public transport (the motor car is, rightfully, banished from the Dome) from my home 35 miles outside London, just as an ordinary punter would, to make my own judgement.

And, here and now, I will make a forecast. The Dome and its surroundings are magnificent. It is, without doubt, the most stunning material realisation of artistic faith and imagination that I have ever seen. This big baby is a winner all right. It will bring wonderment, excitement and en-chantment to the millions who will comefrom all over Britain and from every corner of the world. And as the word spreads about how good it is, nobody will want to be left out. It will be the place where folk memories of the deepest and best kind will be imbedded for an entire generation. Someday we will all tell our grandchildren we went to the Dome AD2000.

A bit over the top? All I can tell you is that as I climbed up on to the roof of the great beast and looked down on its vastness my heart started to hammer. I could see there was still chaos down there. Thousands of workmen, moving like ants, were making the final adjustments to the 14 impossibly large structures that will form the zones, telling us of our history, our faith, our achievements and our future.

Across the vast floor, the dimensions of 10 St Paul's Cathedrals, scores of massive lorries were reduced to Dinky toy size, working around the clock to clear thousands of tons of builders' debris. It looked for all the world like the factory from hell. How could this mess be sorted in just 18 days? But it will. Exactly on time. Exactly on budget. Without a single serious injury. Without costing you or me a penny. Exactly as it was dreamt of by hundreds of gifted, brave people.

It would be impossible to describe all the wonders I saw inside this place. And the gleeful staff, their battered morale now soaring, would not allow me to go inside the zones' structures themselves. But just to be there, to walk through what seemed like canyons and mountains of concrete, was breathtaking.

I could see gigantic mirrors reaching to the roof; immense structures the size of eight-storey buildings whose walls were silently changing colour and shape in seconds; great mechanical leviathans that even Fritz Lang in his masterpiece movie, Metropolis , would not have attempted; soaring walkways and balconies that will take thousands high over the majestic central area, twice the size of Wembley Stadium, and watch acrobats hurtle 300 feet down from the roof.

And at the heart of it all is the biggest showstopper of them all. The great concrete human figure towering, like a smooth-skinned King Kong, nearly to the full height of the Dome, has an almost menacing power. Visitors will be able to tour its innards, through tunnels that bore through the liver, stomach and chest. And they will be warned that courage will be needed. An enormous replica of the heart lies at its core, and in the darkness they will witness what happens when it becomes excited. The sounds and the hammering of this organ, I was told by one workman, are enough to bring on a genuine heart attack.

The Dome and its contents probe all the senses. The feeling is a mixture of awe and even a little fear at the scale of it. This place will turn adults into children. And for children themselves it will be the playground to end all playgrounds. But all of these things, lavish and fiendishly clever as they are, will just be a part of the experience.

From the roof, looking out over the great panorama of Greenwich - a place where history and science have so often been defined and which became, at zero longitude, the Home of Time - a little imagination can transport you forward to Millennium year itself, on a spring morning perhaps, when the teeming landscape is running at full throttle.

You will be able to see armadas of specially built boats, docking at the piers, bringing thousands down this beautiful but neglected river from central London. Thousands more will be pouring up from the cathedral-like Tube station of North Greenwich to spread out along the vast peninsula on the Thames reach. I had made the journey by Tube from decrepit Baker Street in just 20 minutes, travelling through the new Jubilee Line extension - another trouble-racked project that has emerged as a thing of smooth, quiet beauty.

And when they get here, a day will simply not be enough to see everything. I worked it out that to spend just 30 minutes in every zone, to see the five-times daily show, to see the pop concert and movies in the 2,500 seat auxiliary arena, to eat or drink in any one of the scores of restaurants, would take up to 10 hours.

There were moans and groans about the expense of it all. But on a scale of value the Dome leaves all other London showpieces standing. The Greenwich pilgrimage will demand a full day. And for a family of two adults and three children, who will pay £57 or £11.40 a head, it is incredible value. Nor will it be rip-off city; prices have been ordered to stay at high-street levels.

If all this sounds like a publicity blurb, I make no apologies. I came as a mild sceptic. I left as a convert. Later that evening, telling a group of friends what I had seen at this once derelict and forgotten corner of London, I was astonished at their anticipation. Adults and children said they could not wait to get their tickets. And millions will feel the same. I should not have been surprised. All of us, in our heart of hearts, wanted the Dome to succeed. At this momentous moment in history, there is a touch of the child in all of us, and we desperately want to be part of it.

Those who have wept and sweated to create this miracle from a derelict wasteland in just over two years have always had faith. People such as the chief executive of the New Millennium Experience Company, Jennie Page, a civil servant transformed into the most gifted ringmaster since Barnum and Bailey, was said to be "tense and exhausted - but jubilant" as the end came closer. Great showmen and entrepreneurs such as Michael Heseltine, Michael Grade and Sam Chisholm had powerful input too.

And finally, Peter Mandelson, who was perhaps handed the biggest poisoned chalice in the New Labour cupboard when Tony Blair gave him the job of getting the juggernaut rolling, can repeat what he said during the darkest days: "It will be big. It will be magnificent. It will be a great British achievement."

I have now seen the Dome. And I believe that the greatest spin-doctor of them all was doing what politicians rarely do. He was telling the plain, unvarnished truth. So, get your tickets booked. Gather together those who mean the most to you. And roll up for the biggest and the best show on Earth.