Indiana Jones tried to protect it, but what is "IT?" Check out this link to learn more about the Lost Ark of the Covenant. The ARK is a chest built by the Israelites while in the desert after being given the 10 Commandments. The COVENANT is the reaffirmed agreement via the 10 Commandments. So, the Lost Ark of the Covenant is believed to hold the original 10 Commandments given to Moses on Mount Sinai.
http://www.jewishvirtuallibrary.org/jsource/Judaism/ark.html
