Bottom of the Well

The Bottom of the Well (Japanese: 井戸の下 Bottom of the Well) is the smallest room of the mansion in the first game, though it technically is not part of the mansion itself; it is cleared by Luigi in the third area.

Story
Following the Toad's advice, Luigi dropped down to the Bottom of the Well, via a conveniently placed ladder. East was the only way to go, so Luigi explored. At the end of the short room, Luigi peered through the mouth of a stone lion into a sparkling room that looked quite religious. The room was golden and sparkling, and didn't look too run-down and dreary like the rest of the Mansion. It was then Luigi noticed a painting mounted on the far wall. Inside the painting, he saw his brother, trapped inside, pounding on the frame for help! Luigi tried to reach out for his brother, but it was no use. He would have to find a way into that room. Turning back, the dejected plumber came face to face with a Ceiling Surprise. Luigi put the ghost in the dust bag of his vacuum and procured the Key to the Rec Room. Luigi climbed up the ladder back into the Courtyard and used his new Key to enter the Rec Room,where a optional portrait ghost resides.

The Bottom of the Well contains nothing except for a few loose rocks and a lantern as a source of light. The previously mentioned ladder is the only way in or out.

Trivia

 * "Bottom of the Well" is another name given to a dungeon found in The Legend of Zelda: Ocarina of Time video game.
 * While listening closely outside the well, one can hear Mario saying "Hey Luigi! What's the holdup?"
 * If Luigi enters the Bottom of the Well during the blackout, he can see Mario again through the statue, but King Boo will not be visible.