In Raiders of the Lost Ark, what trap sends a huge boulder after Indiana Jones?

In Raiders of the Lost Ark, the idol pedestal triggers the huge boulder trap.

At the beginning of the film, Indiana Jones removes a golden fertility idol from its pedestal inside an ancient Peruvian temple. The substitution is not precise enough to defeat the temple’s mechanism, and the pedestal activates a pressure-triggered trap. Indiana runs through the passage while a massive stone boulder rolls toward him.

The sequence became one of the most recognizable action openings in film history. It immediately establishes Indiana as an archaeologist who combines expertise, nerve, improvisation, and physical endurance. The scene also introduces the danger of removing artifacts from protected sites, although the movie presents that idea through pulp-adventure spectacle.

The boulder is often casually called a “stone ball,” but the specific trigger is the idol pedestal. The temple itself is separate from later locations such as the Well of the Souls in Egypt.