
World Museum, Liverpool
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.
Liverpool, Merseyside

The famous ferry run as a fifty-minute sightseeing loop with commentary, and the truth is children rate the boat above every museum on the waterfront. Wind, wake, gulls, the skyline doing its thing.
Hop off at Seacombe and Eureka! Science + Discovery is directly outside the terminal - ferry plus museum is the assembled Wirral day.
Looking for more water & swimming near Liverpool?

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.

A Tudor hall with woodland walks, a maze and a natural play area in the grounds. Free if you have National Trust membership, and the indoor house is a good rain fallback.

The city's story with an overhead railway carriage to climb aboard and Little Liverpool, a dedicated hands-on gallery for under-6s. Free, on the waterfront, and the window views are half the fun.

Titanic and Lusitania told in the city that crewed them, ship models, and the Seized! customs gallery in the basement where kids hunt smugglers. Free, and the Albert Dock outside is its own event.

South Liverpool's favourite park: lake, playground, ancient trees and the Storybarn, The Reader's hands-on storytelling space in the old coach house. The neolithic Calder Stones are older than Stonehenge, which is a good fact to deploy.

A working Edwardian estate farm with rare breeds, a walled garden and 500 acres of free country park around it. The farm entry is cheap and the pigs are enormous.