The massive 22-foot-diameter boulder was made of fiberglass . To satisfy Steven Spielberg’s desire for more drama, Reynolds designed it to roll an extra 50 feet, requiring a sophisticated hidden arm contraption to reset it between takes. The Illusion of Peru

The set design directly shapes character action.

Surprisingly, the legendary Golden Idol began as a souvenir fertility sculpture Reynolds bought at an airport in Mexico. He adapted the figure, cast it in gold, and ensured its size worked perfectly for Indy’s tense "sand-bag swap".