Compared to the Strange Inscriptions in the Vatican and the Stelae in Gizeh, the Khmer ... the Cogwheel puzzles and collecting the Ancient Relics they protect will unlock the Gearhead Achievement. There are 45 achievements to unlock in Indiana Jones ...

Indiana Jones and the Great Circle has a ton of hidden temples and rooms with head-scratching puzzles around every corner, and perhaps the most difficult are those found in the Khmer Cogwheel Puzzles discovery mission.