We recently took a trip to our local theme park who last year opened up an indoor area called Adventure Inside. There are some typical theme park rides inside including a Swing Boat ride and a Merry Go Round along with some typical seafront arcade machines. There is also a big soft play area that you can visit separately which is why we went.
The soft play area is spread across four levels with multiple slides and climbing areas and also a ball pit area. It is also split into two areas a four and under and a four and over, but when we went children four and under had the run of the whole area as it was during school hours. All of which was for £4.
Oliver had a lovely time as did Leo who was playing with his little friend outside the soft play bit.
I would throughly recommend Adventure Inside as a great place to go during the winter and when we went last Summer it was a lovely addition to the park itself.