In 'Raiders of the Lost Ark', what artifact are the characters searching for?

In 'Star Wars', who trained Luke Skywalker on Dagobah? In 'Star Wars', what is Darth Vader's name before he turned to the dark side? In 'Star Wars', what is the name of the moon-sized battle station destroyed by Luke? In 'Indiana Jones and the Last Crusade', what are the characters searching for? What animal is Indiana Jones famously afraid of? Who played Indiana Jones's father in 'Indiana Jones and the Last Crusade'? In 'The Matrix', who plays Agent Smith? Who plays Trinity in 'The Matrix'?