Ruins Key (Paper Mario)

The Ruins Keys are old keys found in Paper Mario. In Dry Dry Ruins, Mario uses these keys to open several locked doors to advance through the ruins, and eventually reach Tutankoopa, the chapter's boss. There are four Ruins Keys in total.
 * The first Ruins Key is found in the third room visited. It unlocks the door to the room above.
 * The second key is found further in the temple after pouring sand down from another room to reach it. It unlocks the door to the room containing the Artifact.
 * The third is obtained after defeating three Pokey Mummies. It unlocks the door to the deeper parts of the ruins.
 * The fourth key is found in the room adjacent to the hallway containing a map of the ruins. It requires the Super Hammer to obtain, and unlocks the room containing the answer to the Chomp Rock statue puzzle.