Hands-on museums and science centres. Several of the best ones are free.
The story of the village Lever built for his soap workers, with a preserved worker's cottage on the same ticket and £2 trails to pull children round the prettiest streets on Merseyside. A gentle history stop, not a rides day, and priced like it knows that.
A hands-on science centre built precisely for this age group - walk-through lungs and a supersize brain in the new Bodies gallery, inventions to test, and the ferry stop is literally outside. Entry converts to an annual pass, which changes the maths entirely.
Free, indoors and better than it sounds: interactive science aimed at younger children, glassblowing demos, a picnic area and a small playground outside.
Five floors, free, and it covers three things small children reliably love: giant dinosaurs, an aquarium and a space gallery. The best wet-weather day within half an hour.
Hands-on science galleries and a glass rooftop observatory over the Mersey. Small, cheap, indoors and close.
Working steam engines, the story of Cottonopolis, and hands-on galleries in the world's oldest surviving passenger railway station. Free, and the live demonstrations are the bit kids actually remember.
A T. rex skeleton cast, live frogs in the vivarium, Egyptian mummies and a genuinely good natural history floor. Free, university-run, and less overwhelming than the big London equivalents.
Shirts, trophies and match footage across six floors, with penalty shootout and skills games that football-mad kids refuse to leave. If yours do not care about football, skip it - it is exactly what it says.