Theme parks, high ropes and climbing. Check the height limits before you promise anything.
The best age match of anything on this list. Reviewers put the sweet spot at 2 to 10 and say a 4-year-old can do essentially the whole park; the map colour-codes areas by age and puts mini zipwires beside the full-size ones. Budget four to six hours.
High ropes and treetop courses in the grounds at Walton Hall. Reviewers rate the value, but frame it as one for the bigger, braver kids.
A theme park deliberately built for ages 2 to 13 rather than teenagers, so both of them can ride most of it. The classic full-day option on your doorstep.
The cheapest real activity anyone is recommending this summer, and it's indoors. An hour of play for a fiver a head, with picnic benches for when you need to sit down.
Two rides, a 4D cinema, build zones and Manchester's skyline done in miniature bricks. Squarely aimed at 3 to 10, and it knows it: adults can only visit with a child.
Real snow all year round at the venue Manchester still calls Chill Factore. Little ones get the Snow Park with sledging and slides; older kids can learn to ski or board on the UK's longest indoor slope.
Real steam trains between Bury, Ramsbottom and Rawtenstall, with themed family days all summer - Peppa Pig, fairytale specials, the lot. The day rover means you can hop off for lunch and catch the next one back.