Gladiator II” picks up 16 years after the first film ends. When director Ridley Scott was conceiving the original, the approach was, “Build the sets, fight real tigers, shoot real arrows,” says cinematographer John Mathieson.

Ridley Scott’s “Gladiator II” is full of a memorable action scenes, from a bloody showdown featuring CGI baboons to Paul Mescal outsmarting a charging rhino in the Roman Colosseum. But one sequence that is sure to leave audiences with the most questions is a rather insane set piece in which the Colosseum is filled with

Sharks? Maybe not. But sea battles, semi-aquatic creatures and plenty of other eye-popping spectacles were part of the real-life games at the ancient Roman Colosseum.