The London Eye is a great place to start your London visit. You'll get a stunning view over the city, and kids will love the experience. Southbank Center is just a few minutes from the London Eye and offers a great range of family-friendly activities like theaters, street performances, and art exhibitions.
The Natural History Museum has fossilized skeletons of huge creatures like whales and dinosaurs. Plus, it has a dedicated children's section that's interactive and informative. Afterward, take a stroll through Hyde Park. You can rent a boat, visit the Diana Princess of Wales Playground, or have a picnic.
Hogwarts fans will delight in this experience. The Warner Bros Studio Tour takes you behind the scenes of the Harry Potter movies, even showcasing an original Hogwarts Express train and various sets. Afterward, enjoy a walking tour of famous Harry Potter London locations. Including King's Cross Station, Leadenhall Market, and Piccadilly Circus. Don't forget your camera!
If you have more time, you can consider visiting some other popular attractions like the Tower of London or Madame Tussauds. Alternatively, you might extend your stay in Hyde Park by visiting the Serpentine Gallery or going to the Serpentine Lido for a swim. With less time, it might be worth scaling back and focusing on one or two sites a day.