Need ideas for a boys 8th birthday party. He's very active/adventurous but party in March means I'm not keen to do anything outdoors as the weather is too unpredictable. Was looking for a wipeout/inflatables type swimming party but cant find one locally (halesowen/hagley type area in west midlands). Looking at climbing walls but no keen on go ape for weather reasons. He was asking about theme parks but that seems very expensive and to me is just a day out not a birthday party. Can anyone give me inspiration?