You need FastTrack tickets.
Definitely one of the best parks we've been to, ever. BUT. It's busy, really busy, even in October, with up to a 30 minutes wait, in 27 degrees and direct sunshine!!!!! I'd recommend the FastTrack if you can afford.
Siam Park
Thank you for taking the time to share your visit on TripAdvisor. We’re delighted that Siam Park stands out among your travel memories—that means a lot to us. We also appreciate your honest feedback about the less comfortable parts of the day; those matter too. We hope to welcome you back for another adventure with us.