Hands-on museums and science centres. Several of the best ones are free.
The Lovell Telescope is one of the largest steerable radio telescopes on Earth and it silences children on arrival. The First Light Pavilion and the new Curious Titans exhibition do the rest; the arboretum does the running about.
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.