Wirral, Merseyside
Billed as the UK's biggest soft play, and the scale is the point: multiple full-height frames, slides in formation, and enough floor to lose a rainy afternoon entirely.
It is a long drive for soft play - so make it an event: the Black Pearl driftwood pirate ship and New Brighton's seafront are two minutes away and free, which turns a wet-day fallback into a proper day out.
Looking for more soft play & indoor play near Wirral?
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.
Beach, marine lake, Fort Perch Rock at the river mouth, and the driftwood Black Pearl pirate ship built from beach findings that children treat as the best playground on Merseyside. Chips on the front to finish.
University of Liverpool's gardens above the Dee estuary: family trails, a wildflower meadow, a good playground and views across to Wales. Quieter than the National Trust circuit and better value.
Britain's first country park: a clifftop path above the Dee, a beach for fossicking below, and a visitor centre with bird hides. Wild-feeling without being remote.
A small, friendly Wirral farm park with animal handling most days, a maize maze in late summer, and Thurstaston Common and the beach five minutes away for a two-stop day.
A free community farm under Bidston Hill: pigs, goats, alpacas and hens, a woodland on the doorstep, and a café doing proper bacon butties. One of Merseyside's best zero-cost mornings.