There will be a 41-gun salute in Green Park to mark Prince Charles' 70th birthday.
It will be fired by the King's Troop Royal Horse Artillery (KTRHA), and take place near the norther edge of the park, a short distance from Constitution Hill.
Important note: If you're a tourist then be aware that you're required by law to stand outside Buckingham Palace and sing him 'Happy Birthday'. And that is not a joke. You also have to buy him a birthday present. And give him the bumps.
Craig’s review of Green Park – “Green Park is the great un-loved park of London. No one has ever said: "I know -- let's take the kids to Green Park for the day". No one ever goes there on a sightseeing tour. No one takes photographs of it and nobody wants to scatter their ashes in it. They couldn't even be bothered to give it a proper name: Green Park. That's like calling an orange and ora… continued”
Hire a deckchair in one of London’s parks – 1 Mar to 31 Oct 2018 – Have a nice, relaxing sit-down and doing a bit of people-watching in one of London's Royal parks, by hiring out a deckchair.
Hire a pedal boat on the Serpentine lake – 1 Apr to 31 Oct 2018 – Spend a pleasant afternoon pedalling around in a little hire boat on the Serpentine, or catch the sun-powered SolarShuttle.
Get a closer look at the Albert Memorial – First Sun of the month (Mar to Dec only) – Go inside the Albert Memorial's railings and see one of London's finest looking monuments from up close
Listen to a speech at Speakers’ Corner – Every Sun (around noon) – If you visit Speakers' Corner at Sunday lunchtime you can listen to an orator stand up and discuss whatever they like -- all in the name of free speech.
Sunday football on Hackney Marshes – Every Sun – Hackney Marshes is the home of Sunday league football, with over 70 matches played between dozens of amateur teams.
Fireworks display at Kingsmeadow – 2 Nov 2018 – Kingston's annual fireworks display with a funfair and food stalls will be held at Kingstonian FCs football stadium.
Alexandra Palace Fireworks Festival – 2 to 3 Nov 2018 – The fireworks display at Alexandra Palace will include a big bonfire, ice rink, children's funfair and German beer festival.
Check out our guide to all the daily parades in London
Here are some more free events in London if you want a cheap day out
If you enjoy Green Park then you might like to visit Hyde Park (walk it in 18 mins or catch the tube from Green Park to Hyde Park), Kensington Gardens (catch the train from Green Park to Kensington Gardens), Regent’s Park (catch the train from Green Park to Regent’s Park), St. James’s Park (you can walk it 10 mins) and Victoria Embankment Gardens (walk it in 20 mins or catch the tube from Green Park to Victoria Embankment Gardens)
Disclaimer: Event details can change at short notice and you should reconfirm everything before making plans