Hi the missus is taking our 3 year old boy down to see her sister in Atherton for a few days. She doesn't have kids so will be clueless at suggestions for places to take him. Anything reasonably nearby, within 15 miles say, such as decent soft play, parks, swimming pools etc. thanks
Pennington Flash, Haigh Hall and Walton Gardens are decent parks that spring to mind. Train into Manchester and you have MOSI which they'll no doubt enjoy.