Even the most die-hard Jurassic Park fans don’t know everything that went on behind-the-scenes.

The highly anticipated film Jurassic World is set to hit cinemas this week, so it’s time to take a trip down memory lane and examine our favorite dinosaur franchise.

From hidden cameos to strange animal noises and natural disasters, there are a lot of secrets hidden in these films.

Click through the gallery above to see 10 things you didn’t know about the Jurassic Park franchise!