London is the rare world capital that treats children as full citizens, and most of the best of it is free. The Natural History Museum hands over a hall of dinosaurs, the Science Museum's Wonderlab turns physics into something you push and pull, and neither charges admission, which means a rainy morning costs nothing and a restless eight-year-old can leave the moment the magic wears off. The parks do the rest: Kensington Gardens has the Peter Pan-inspired Diana Memorial Playground, Regent's Park folds in London Zoo and its 650-odd species, and Hyde Park's boating lake gives everyone a reason to sit down. For the committed, the Warner Bros. Studio Tour delivers Hogwarts to any child who has ever held the books.

The landmarks earn their reputations without trying too hard. A turn on the London Eye, a Thames boat past Tower Bridge, and the Tower of London itself stitch a thousand years of history into an afternoon that never feels like a lesson. Come evening, the West End is genuinely all-ages, with Matilda and The Lion King built to hold a child and a parent for the same two hours, while Covent Garden's street performers cover the gaps for free. Borough Market and a proper plate of fish and chips keep the eaters happy. The hotels are where families buy back their sanity, with family rooms, kids' concierges, and babysitting, or apartment stays that add the extra bedroom and a kitchen, so a big, fast city becomes one you can actually do at a child's pace.