Venue Ideas For Little Einsteins Party For A 4 Year-Old

Desperate for ideas of where to have a Little Einsteins party in September for my 4 year-old daughter. Tired of normal parks and bonce house places. Looking for a great party room , maybe, where we can have lots of balloons and a June character to entertain the kids. Looking for a unique, kid-friendly place in Orange County, CA. ANY ideas/suggestions are greatly appreciated! Thanks for your time! :-)