A dedicated area has been set up for well-wishers to leave gifts in memory of the Queen, with the piles of flowers, soft toys and marmalade sandwiches growing by the minute.
From young to old, tens of thousands flocked to the park, with many people seen in tears at the sight of what was before them.
Groups of school children hand in hand and wearing high-vis jackets were spotted throughout the day as teachers took the opportunity to show them such a huge moment in history.
Jenny Slatcher took her one-year-old daughter Charlotte to lay down red roses and show her “how loved” the Queen was.
Speaking to the Express, the 31-year-old from Guildford, said: “It’s a part of history and it’ll be quite nice to tell her one day that we went up to see the tributes ourselves and to show her how loved the Queen was.
“It’s been an emotional day and I’ve been more emotional than I expected but seeing everyone together and all of the flowers has been really special.
“The Queen could have wanted this, to see people uniting and spending time together after a difficult few years.”
Childminder Tracey Johnson, 60, took the toddler trio she looks after to the park today to spot Paddington bear toys among the piles of flowers.
Ms Johnson, from Streatham, London, said: “I wanted to come to pay my respects in person. She was a lovely lady and she’s always been in my life, and I just think it’s really important to share this moment with our boys.
“It’s a very sad day for everybody. She was loved by people of all ages, from pensioners down to little ones like these, and she served for 70 years so it’s only fair that we come and thank her for that.”
Despite the crowds of people, Evie Norman described the “calming silence” in London, which “really showed” how much Her Majesty meant to the nation.
The usually buzzing streets around Buckingham Palace were still and little could be heard other than the crunching of fallen autumn leaves under the feet of visiting mourners.
Evie, 26, from Kent, said: “It is very sad, but we are living in history. I have never witnessed anything like this.
“It’s an emotional time but everyone has come together to celebrate her life so there is a lovely atmosphere here. We have spoken to so many people we have never met before to speak about the Queen, who was an inspiration to so many.”
People are thought to have travelled from all over the world to thank the Queen for her 70 years of service, with letters and cards signed off from Bangladesh, Romania, and Australia.
One lady, Stephanie, touchingly left a bunch of flowers for the Queen that was last week on her own mother’s coffin.
In a letter attached to the bouquet, she wrote: “These flowers are from her [her mother’s] coffin last Monday.
“Mum would have been thrilled and honoured to think we brought them to pay our respects to our dear Queen.”
Members of the public are being urged to take off plastic packaging before laying down bouquets so the later job of turning them into compost is made much easier.
In a statement on their website, Royal Parks said: “Unfortunately, no gifts and artefacts will be accepted, and the public will be asked not to bring these to the parks.
“Non-floral objects/artefacts such as teddy bears or balloons should not be brought.”
Some visiting the park today may have also got a glimpse of the new King as he was driven into Buckingham Palace and waved to crowds queuing down The Mall.
But many who travelled in by tube were hit by severe travel disruption due to “power supply” problems.
The entire Victoria Line was suspended in the morning and there were long delays on the Piccadilly Line throughout the day.
It meant only one of the three lines – the Jubilee – serving the station nearest Buckingham Palace had a good service.