Well,unfortunately they've just knocked the outdoor pool down so that they can put some flats there but the north side beach is lovely and you don't have to spend money on annoying rides and slot machines. Just round the corner is Peasholm Park which has some nice walks, a tree trail, and on the other side of the road a miniature train engine which will take you on a short ride as far as the Sea Life Centre (very good but can get heavingly busy if the weather's a bit rough) If you've got a car you can go to Dalby Forest which costs £7 to go through the toll but there's a few lovely children's play areas, plus a nice visitor's centre and Go Ape! and a mountain bike trail if you're that way inclined. TBH if you're not usually at the seaside (I live here so it can be a bit wearing!) I'd do all the proper tacky seaside stuff on the South Bay - fish and chips, visit the Lifeboat house and give some money to some ladies in too much blue eyeshadow, have some candyfloss, dig some holes, waste some money on rides and come back with a very happy DD I would have thought!!) Also, while you're over this way, Whitby is more than worth the 20 minute car ride, just for the cute lanes and the walk up all those steps! Also a 10 year old might enjoy the Dracula element, depending on what type of lad he is. Hope this helps!