We visited the Omnimax theatre with our kids over Memorial Day weekend. It is located within the St. Louis Science Center. The cost is $9 for adults, and $8 for children, but you can find buy one get one discount coupons on various websites. The theatre itself is impressive. You watch the movie on a screen that covers the entire dome and I believe they said it was five stories high. Sit towards the top or you will be stretching your neck the entire time. It can be a bit intense, so sometimes I had to look away from the screen for a bit. They usually have two selections playing at various times throughout the day. We chose Air Racers because it was playing in the next 15 minutes. To see the other movie (Flight of the Butterflies), we would have had to wait another two and a half hours. We have three girls, ages 12, 7, and 5. They were really bored with the air racer movie and would have definitely liked the butterfly movie better. It's fun to experience, but just make sure you go to a movie everyone will enjoy.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.