Sea World is a fantastic park! Legoland is a decent park for younger kids, but older kids or those disinterested by Legos may not find it that enjoyable.
If I had to pick one, I'd go with SeaWorld. There is a wider range of shows and rides that should appeal to everyone in your group. Legoland skews much younger.
Another vote for Legoland. We were there with a 9 and 7 yr old and they loved it. Your kids are the perfect ages, you can always do Sea World next time.
Legoland as it just seems like a brighter, happier place! Friends of ours just went there with kids the same ages as yours and had the best day together! Have fun.
Our Authorized Disney Vacation Planners are here to provide personalized, expert advice, answer every question, and uncover the best discounts.
Let Dreams Unlimited Travel take care of all the details, so you can sit back, relax, and enjoy a stress-free vacation.