The Queen has described Diana Princess of Wales as a "remarkable human being".
Princes William and Harry, their father Prince Charles, and Diana's brother Earl Spencer were among those who attended the opening of the memorial fountain.
Diana's mother Frances Shand Kydd, before her recent death, described the memorial as having a "lack of grandeur".
But a member of the Memorial Foundation Committee said that Diana "was not grand, she was the most unstuffy person I think I know".
Have you seen the fountain? Is it a fitting tribute to Princess Diana? Would you have chosen a different memorial? Send us your comments.
This debate has now closed. Thank you for your comments.
Just like the princess, beautiful in its complicated simplicity.
Leigh Broome, Concord, North Carolina, USA
It does indeed look like a log ride at Alton Towers. What a complete waste of money. She was an amazing woman - but there are many more that do just as much if not more to help the poor and marginalised and get no recognition. Having said that, if this is the kind of recognition you get, perhaps they'll be glad they don't get any.
Diana would be horrified at the amount of money spent on what looks like a concrete water gully as seen in many underdeveloped countries to handle heavy rains.
Chris, London, UK
I would consider that the cost of this fountain would have been better spent on education or healthcare.
Veronica, Pune, India
It is appalling! Anything less suited to Diana is hard to imagine, and I am not even a fan of Diana.
Janice Quinn, Wirral, UK
I like it and more useful than a statue. Given Diana's love of children, I think something that attracts children is the perfect memorial. Nice to see the Spencers and Windsors out together- never did believe the media rift stories. Thought the Queen's speech was excellent.
This is an utter disgrace and insult to Diana. This is not exactly a world class memorial to a world class lady is it? Seven years almost, and they've come up with something looking like a log flume! Ok, I can understand the concept in the idea, its ingenious but it isn't fitting at all. She deserved better than this, seeing as it took so long. The people should have had a vote on different proposals so we wouldn't have such large criticism.
Ian, Wiltshire, UK
I think it is actually quite tasteful and fitting. Set in one of London's more prestigious parks, it adds an air of tranquillity and provokes thought without being pompous or ostentatious.
Andy, London, UK
Why has it taken so long to have this memorial built? Surely it should have been done in the year that she died? A nice thought, long overdue, and could have been more inspiring and reflective of Diana. And why has an American designed it - surely the people to decide the most fitting tribute were her family and her sons.
A charity foundation is what I believe she would of wanted.
Aaron Delaney, UK
Princess Diana was loved by millions. This memorial fountain may not be the most grand of tributes, but it will provide a calm, relaxed environment which everyone may appreciate, just like the Princess herself. The running water is a sign of life and as such can only be the perfect tribute to the loss of a truly lovely lady.
James, Lindfield, Sussex
A hospital or a hospice should have been named after her, it would have been more appropriate after all the good work she showed an interest in.
Hilary A Breen, Nairn, Scotland
Wouldn't the 3.6 million pounds have been better given to one of her charities than pay for this?
This is a beautiful, bold and stunning memorial. Whoever made the brave decision to go for a probably controversial design should be applauded. I think Diana would have loved the fact that it's going to be a big hit with children and they will get a lot of fun out of it.
A quiet reflective memorial; an excellent modern memorial to a modern princess; the memorial asks visitors to reflect on Diana in a very similar way to the Vietnam memorial which asks visitors to reflect - both are not intrusive, both ask the visitors to think and remember.
Paul Corser, Alton, UK
A memorial for Diana is a nice thought for a lady who just showed the world that despite her status, suffered like so many others. However, a memorial from the Queen could be perceived as a shallow gesture from one who didn't approve of her and possibly an attempt to boost her reputation in the public eye. But let us forget this and hopefully Diana may rest in peace, while not forgotten.
A proper, classic fountain or waterfall would have been a beautiful, fitting tribute. This is an eyesore and a complete waste of money. It is an insult to Diana's memory.
Carole Young, Glasgow, Scotland
Awful structure. What a hazard to children. I would be sitting on egg shells if my kids were playing there!!
Caren, Palmdale, California
Her family seem happy with it, her friends seem happy with it, the only people with a problem are the great British public, who obviously knew her better than everyone else because they used to read about her in the papers... Get over it.
Alex M, London
My son summed it up this morning Diana was a people person and a statue would have made her look down on people and she was not like that so the fountain is at her level, with the people she loved and cared for, after all she was the people's princess, loved and adored by all
Shirley Buckley, Thurmaston, Leicester
As Diana loved children I think the memorial is fitting as children will enjoy playing in the water. However I think it was in very poor taste that Prince Charles was there, he was her ex-husband and in view of his long standing affair a pretty poor one at that.
Anne, Bristol, England
I don't think that this fountain is a good representation of Diana. She was a very elegant, young and enthusiastic lady - what is this fountain? - a plain, flat piece of concrete with water in it. Yes, it is ok for a feature in a park, but it doesn't exactly jog your memory regarding Diana. A statue of her would have been much better and more dynamic.
JG, Tonbridge, Kent
I've only seen it on TV but it looks a pleasant spot for rest and reflection. Of course, children will be drawn to it but I am not sure that it is a suitable place for children to play, unsupervised, bearing in mind that young children can drown in a few inches of water. Some parts of the 'stream' looked very fast flowing and, I imagine, that the marble would be slippery. The placid section looked quite deep.
Joan, Deeside, Wales
What a waste of money. £3.6m would have gone a long way to support some under privileged members of our society rather than pay for a memorial to a rather over privileged one.
Simon, Bristol, UK
Diana already has a hospital named after her, The Diana Princess of Wales Children's Hospital in Birmingham. A place bringing comfort to suffering children and families - just as she did in her lifetime.
Angela Tetstall, Birmingham, England
I have to admit when I first saw it, I thought it looked like a municipal sewer outlet, but on reflection it has grown on me. Memorials take time to be accepted, many people thought the Albert memorial ghastly but it has grown in our affections. The British establishment would never allow Diana's memorial to outshine living royally, the outpouring after her death shocked them to the core and they have made attempt after attempt to smear her. There is no getting away from the fact that Diana touched something in people so profoundly that we are having this debate today. The memorial I see reflects that, in its use of the elemental substances of stone and water cast in the form of a circle. Yes now I think of it, it is a fitting tribute.
Barry, Hornchurch, Essex, UK
Just what will it look like when the graffiti appears on the walls, empty drinks cans and rubbish are floated down? It's another daft design sanctioned by people who have no connection with reality. Diana's true memorial lies with the people she touched. A friend of mine answered the door to his modest house and there, unannounced, was an unescorted Diana, Princess of Wales, who had come to visit his daughter whom Diana had met in hospital. His daughter, a teenager, died soon afterwards from cancer but with the memory of a life touched by an extraordinary woman, a 'Royal' unafraid to show her love to others.
David, Manchester, UK
British politicians and royalty never really understood Diana - this memorial shows it...
It's interesting to see that many of the nicer comments about Diana come from countries other than the UK. Why the 'sour grapes' from you Brits, envy perhaps? Your princess was a warm, beautiful caring person who was also very brave. She showed the world that it was safe to touch an AIDS patient and treated landmine victims and the homeless with great compassion. She took the time to acknowledge them as fellow humans where many ignore and try to pretend they don't exist. It's easy to give a few dollars to a charitable cause and feel good about yourself, but Diana showed us all what true compassion is. Hers came from the heart. I believe she made many people feel guilty of lack of caring and they resent her for that. If anyone deserves a memorial it is Diana the True Princess.
PW, Cocoa, FL
What a waste of money. This does nothing other than add to the cult status surrounding Diana and is utterly pointless. A better use of the money would have been something like a memorial (children's?) hospital. I'm sure she would have regarded that as being a much more valuable use of funds.
It will look great until the first crisp packets, coke cans and supermarket trolleys find their inevitable way. And the Autumn leaves and grass clippings don't bear thinking about. I hope they have a daily cleaning budget!!
Brian, Grimsby, UK
It seems such a plain memorial to Princess Diana even though it cost so much money. There is nothing obvious linking this memorial to the life and works of the mother of the future heir to the British throne.
Dina, Limassol, Cyprus
A lot of people do good charity work best of their capacities, as their time and resources will allow. Diana did some great work, and inspired others, but she was not particularly special in this particular sense, since a lot of unknown charity workers also inspire others. She wasn't nicer or kinder than someone who may be giving up their spare time to work in a homeless shelter for instance. Surely a memorial tree would have sufficed; that's what most people get, plus the tree has some use for the environment. Best way to remember her is to be like her, and help charities, be it with time, or a regular donation.
Naseem Ramsahye, London, UK
Caron of England-yes the Queen Mum may have done more for the UK-a debatable point- but she had 80 odd years longer than Diana to do it in! Diana related well to the average person in the street and people loved her for that. An understated memorial like this is preferable to anything flashy-but I think William and Harry should be the ones to unveil it, and not the mother-in-law!
Sadie Carr, Goring, UK
How can anyone get so emotional about someone they never met and only saw on the TV screen ? Anyway surely a better memorial would be not to waste loads of money on a fountain, but something more simple and give the rest to the charities she was affiliated with.
Jon, London, UK
It is always nice to have new and interesting things to see in the capital. Whether it is a fitting tribute is another question. I have believed that a statue is the only way in which to pay tribute to someone such as Diana. Hyde Parks newest water feature, will be just that - a water feature.
I really do think William and Harry should unveil the memorial. If they decline then her brother should do it.
I must admit to being a huge fan of Diana. She was the beautiful face of the royal family and I will be sure to visit the memorial. She did so much for Britain, now its time to show her how grateful I am.
Russell Kent, Elephant and Castle
Elegant and made from quality ingredients. Calm and soothing in places and turbulent with strong uncontrollable undercurrents in others, and controversial. Yes this is the perfect memorial to Princess Diana.
Looks like something you'd find in a theme park rather than a memorial. Shame it took so long to happen and a bigger shame more thought wasn't put into what a fitting memorial really would be. Reinstating HRH and a statue of her I think would have been more appropriate. She was, after all, the mother of our future king.
Peter, Manchester, England
It is ridiculous. Diana is a great person and a symbol of the Empire of the Sun, and it should be treated as such. She was loved by millions of people around the world.
Surely enough has been done for the royal family already, the money could have been better spent, instead of wasting it celebrating people who are just a drain on the countries money and resources.
James Long, Cardiff
I'm sick of this. She was a very wealthy woman who used a fair amount of her resources for good. Mother Teresa of Calcutta died the same week as Diana, lived in poverty and devoted everything she had to helping anyone she could. Yet I don't even remember the last time I heard anything about her, let alone seen a £3.6m memorial dedicated to her! If Diana really was such a saint, then I'm sure she would have preferred that colossal amount of money to have been spent on the poor, sick and needy.
John, Southampton, UK
When she was divorced from Prince Charles she continued to do good works choosing her own charities and causes that were dear to her to patron. The Queen Mother did a great deal for the UK, no doubt. She also deserves a memorial for her decades of service to our country. Diana, unfortunately did not live as long as the Queen Mother and who knows what she might have accomplished had she been blessed with a long life. She absolutely deserves a memorial and those who are against it are simply crass.
Anna, London, UK
A memorial needs to pass the test of time. Are her accomplishments in the UK history significant enough to have future generations visit the memorial? Or are we all just being sentimental about this.
Sung, London, UK
Although I feel a memorial to Diana is long overdue, I am not sure whether this fountain is the best way to remember her. I also feel it is rather hypocritical having the Queen to open it, when she was "forced" to return from holidaying in Scotland when Diana died. I feel a Children's Shelter or clinic named after the Princess would have been more appropriate.
Linda, Manchester, UK
It's different and interesting, just like she was.
Paul, Bracknell, UK
Nothing will ever replace the 'real' her. I rather she was still with us today - only happier.
Ian C, Midlands, UK
The memorial is beautiful and the context of the design is great and 100% Diana. My only thought is why did it take so many years to get the memorial organised?
WP Derbyshire, London
Nice fountain. Shame it's aim is to further idolise Diana. She wasn't an angel and she got a lot out of her good works. Thousands of other people in this country do a lot more work than she did, for a lot less recognition. It's about time the UK got over their fixation with the cult of personality surrounding her.
Kaz, Hull, UK
We already have the Diana memorial walk and playground in Hyde park, do we really need another memorial? This one up man ship of grief is starting to get distasteful.
David, London, UK
I would prefer to see a memorial to the Queen Mother as she did more for charities and the UK.
Its just the sort of place kids will play in the summer. This is exactly what she would have wanted.
Toby Cave, London, UK
Too little, too late! A fountain hidden away in one London park has nothing to do with the Princess or her life. It is a disgusting "tribute." Diana deserves a statue and a hospital named after her, etc.
Lisa, Nova Scotia, Canada
It's nice but it does not really help anyone like she used to.
Tom Jones, Barcelona, Spain
Just as long as it isn't in Wales that is fine. She was labelled "Princess of Wales" but she had no interest in our country and visited only twice in her lifetime. Give the money to charity where it can be used properly.
I completely detest the Diana memorial. Its just a pool of water that encircles a part of Hyde Park. A statue of the peoples princess or a re-naming of a London hospital would have sufficed.
Gary Jackaman, Ipswich, UK
"She has left two great boys who need to be reminded of their dear mother". Do not all kids need to be reminded of dead mothers? Why the preferential treatment? Strictly speaking she wasn't even monarchy.
From the photos I have seen it would be at home on a golf course. The money that was spent on it would have been better spent on research or training doctors to help in the fight against aids.
Clive, Dartford, UK
Diana, princess of the world, that fountain is a beautiful tribute, we will never forget Diana, beautiful humanitarian princess her memory shall not fade ever. God bless your soul.
It seems to me that she doesn't need a memorial - scarcely a week passes with out a mention of her in the papers, on the news and in magazines. You would have to be a hermit on Mars to have forgotten her- even if you wanted to.
Derek Blyth, Bolton, UK
I don't think Dianna needs a water fall to be remembered, she was such a great person. I personally like what has been done in her name and will enjoy visiting it on a warm summers day.
Wayne, Byfleet, UK
London is stuffed with memorials to over privileged royalty, and members of the armed forces -who fronted squalid imperial adventures. It's about time we replaced these with memorials to ordinary people who have made significant contributions to society.
Michael McCarthy, London, UK
The fountain is indeed a fitting tribute to Diana and important for her children. I have the greatest respect for the Queen who will be there Tuesday, because I think she has not been treated very respectfully throughout this whole affair.
I am not too keen on the design, but I am glad that at long last there is a memorial for Diana. Let's hope it is looked after and kept clean and tidy.
WB, Wales, UK
It certainly couldn't be accused of being tasteless or over the top I suppose, which was always a consideration. It doesn't strike me as being overly inspiring either, but I will reserve judgement until I visit it.
What an absolute waste of money, I suppose it could be used as a boating lake for model boats.
Lester Stenner, Weston Super Mare, UK
I went down to have a look at it yesterday and think it is a wonderful and beautiful tribute. Princess Diana wasn't a flash, showy person, and I think she would love the fact that this is something children will be able to play in.
Nikki, London, UK
There are plenty of more worthy souls up and down this country just as deserving as Diana for a memorial. Why should she be remembered nationally? What lasting contribution did she make to society? OK she was charitable but so are many of us lesser mortals. Its a shameful waste of money and we should feel cheated.
Ed H, UK
Is this really what she would have wanted? Some water flowing through an ugly concrete oval in the middle of a park? Surely she would have wanted our money to be spent on something that would help people, like a hospital or something like that.
Whilst I agree with Alan of Manchester that it shows peace and gentleness which Diana had in abundance, I do feel that there should be some sort of likeness of Diana on the site as well. After all she was beautiful and I think people would feel a greater closeness to the Princess of Wales if this was the case.
Susan, Hull, East Yorkshire
Is this the best they could do as a memorial to Diana, Princess of Wales? It does indeed lack grandeur, no doubt that was intentional. She deserves better than this.
It's a total and utter waste of time. Money would be better spent on one of the charities that Diana supported. And why is the Queen unveiling it - I though that those two did not get on?
Al Oddie, Ulverston, Cumbria
I think it is a great memorial, it shows how peace full and kind she was, with the gentle flow of the water.
I feel the memorial is a great tribute to my super lady regardless of how the tax payers are going to react. She has left two great boys who need to be reminded of their dear mother. Whatever transpired during her life should not be dragged into this memorial. Nobody is perfect. I wish the Princess herself had time to write down what she would have liked to be remembered by. I think Diana would have loved to build a big hospital built for the poor in any country of her choice.
Perfect, for the serial weepers.
Gerry Noble, Salisbury
Perhaps the fashion industry will do a better job of paying tribute to her somehow. After all, she brought a tremendous amount of attention to British designers. Perhaps they will create a monument to her somewhere that would really be more fitting. Or perhaps the Aids foundation will give her a fitting monument for all her work with them. Then again, maybe those who she worked with to rid the world of land mines will find a way to give her a fitting memorial. Diana may not have been "grand" but her accomplishments and contributions to the world certainly were.
Lisa, Fredricksburg, USA