There will be a 41-gun salute in Green Park to mark Prince Charles' 69th 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.