The Boulder at Indiana Jones Adventures is one of the most iconic and thrilling elements of the ride. Guests on the ride are sent hurtling through a temple, chased by a giant rolling boulder that appears to be just inches behind them. But how does this impressive effect actually work? The boulder is actually a large, lightweight ball made out of fiberglass and other materials. It’s attached to a track system that is hidden from view, so guests can’t see how the boulder is propelled forward. The track is a series of curved rails that guide the boulder along its path. The boulder is mounted on a metal frame that is attached to a motorized system. The motor moves the frame forward along the track, which causes the boulder to roll forward at a speed that matches the ride vehicle. This creates the illusion that the boulder is chasing the guests. To make the effect even more convincing, the boulder is covered in a special material that creates a realistic-looking texture and helps it blend i...