Have a look at the tourist info \link{http://www.pooletourism.com/\here} look under things to do, then a-z what to do. It list parks soft play, trains etc.
we like to go to
\link{http://www.adventurewonderland.co.uk/\ used to be called alice in wonderland park}
\link{http://www.farmerpalmers.co.uk/\farmer palmers}
\link{http://www.paultonspark.co.uk/\paultons park}
\link{http://www.monkeyworld.org/\haven't been here yet but hoping to go soon Monkey world}
Could go on for ages, but have a look and I am sure other mumsnetters will also give you more ideas.