The film is family fun with a rocky romance between a trouser-wearing feminist adventurer Lily (Emily Blunt) and the mysterious tourist-trap Amazon tour guide Frank (Dwayne Johnson), but here are a few things to know.

1. Don Aguirre was a real figure. He rebelled against the Spanish king and he did have a daughter.
2. Prince Joachim was also a real prince and World War I wouldn’t go his way.
3. Submarines were used during World War I.
4. The Florida citrus industry wouldn’t figure out how to make concentrated orange juice until World War II.
5. “Proxima” means next in Spanish.

Other things you might want to know:

1. There were headhunters in the Amazon. Several tribes of the Jivaroan group in Eastern Ecuador and Northern Peru did take heads as trophies. But it also became an industry for tourism.
2. There are no hippos or elephants native to South America.
3. Piranhas are the victim of bad press. The Smithsonian says Teddy Roosevelt is to blame. Piranhas can’t clean a living human to bare bones in five minutes. Piranhas typically eat insects, fish, crustaceans, worms, carrion, seeds and other plant matter. Some piranhas are vegetarian and some eat other piranhas.
4. Forget the piranhas…what about those animals that prey on them: the crocodile’s cousin, the caiman. Caiman eat piranhas as do river dolphins and heron.
5. According to WorldAtlas, “one of the most feared animals of the jungle are venomous snakes,” and the Amazon has ten venomous snakes. And then there are the five non-venomous constrictors of which the Amazon has five.