Princess Peach's Castle

Princess Peach's Castle is the main hub world of Super Mario 64. Nearly all courses and levels are accessed in Princess Peach's Castle. There are several floors.

Castle Grounds
Main Article: Princess Peach's Castle/Castle Grounds

The Castle Grounds is an area that surrounds the castle. It is where the player starts. The only level accessed here in unpersonalized copies is Vanish Cap Under the Moat.

First Floor
Main Article: Princess Peach's Castle/First Floor

The First Floor is the first main area of the castle, accessed by the Castle Grounds. It usually contains Bob-omb Battlefield, Whomp's Fortress, Jolly Roger Bay, Cool, Cool Mountain, Princess' Secret Slide, Secret Aquarium, Tower of the Wing Cap and Bowser in the Dark World. It also contains the paths to the Second Floor, Castle Courtyard, and Castle Basement.

Castle Courtyard
Main Article: Princess Peach's Castle/Castle Courtyard

The Castle Courtyard is a sub-area of the First Floor. It only regularly contains the path to Big Boo's Haunt, and also has the L is real 2401 statue.

Castle Basement
Main Article: Princess Peach's Castle/Castle Basement

The Castle Basement is the second main floor unlocked in the game, unlocked after beating Bowser in the Dark World. It usually contains Hazy Maze Cave, Lethal Lava Land, Shifting Sand Land, Dire, Dire Docks, and Bowser in the Fire Sea. Other notable things here are the first toad that gives the player a star, both encounters with MIPS the Rabbit, and the pillars needed to drain the moat and unlock Vanish Cap Under the Moat.

Second Floor
Main Article: Princess Peach's Castle/Second Floor

The Second Floor is the third main floor unlocked in the game, unlocked after beating Bowser in the Fire Sea. It usually contains Wet-Dry World, Snowman's Land, Tall, Tall Mountain, and Tiny-Huge Island. This is the only floor that only requires a certain amount of stars to pass, and contains the Mirror Room. In the DS remake of Super Mario 64, it also contains Chief Chilly Challenge.

Third Floor
Main Article: Princess Peach's Castle/Third Floor

The Third Floor is the last main floor unlocked in the main game. It contains Tick Tock Clock, Rainbow Ride, Wing Mario Over the Rainbow and Bowser in the Sky. It also contains the endless stairs.

Rec Room
Main Article: Princess Peach's Castle/Rec Room

The Rec Room is a sub-area of the First Floor that is exclusive to Super Mario 64 DS. It contains several minigames, Sunshine Isles, and Goomboss Battle. Peach's Balcony is also located here.

New Floors & Areas
There are several floors added by the Personalization A.I. that are also believed to be based off of unused content.

Castle Crawlspace
Main Article: Princess Peach's Castle/Castle Crawlspace

The Castle Crawlspace is a supposed floor before the First Floor is unlocked, as the First Floor will be locked and must be unlocked by a Bowser level in the Castle Crawlspace. The Castle Crawlspace would be accessed by crawling into a hole in the castle wall in the Castle Grounds. It is a small maze that needs to be crawled around. It contains several levels including: Shipwreck Seas, Ghastly Garden, Sparkly Space, Flip-Flop Facility, Arcade Age, Crawlspace Crack, Secret Sky, Tip-Top Tower, Shadow Cap in the Shady Sands, and Bowser in the Freaky Forest. This level has the count for the most amount of levels in a single floor. When this appears, Bob-omb Battlefield can usually be accessed in the Castle Grounds through varying means.

Castle Attic
Main Article: Princess Peach's Castle/Castle Attic

The Castle Attic is a new floor that is the attic of Princess Peach's Castle that leads to the castle roof. It is first unlocked by entering the Pipe to Another World, but a door to it will appear on whatever floor the player has as the top floor. It contains Candy Canyon, Ocean Oasis, Lava Lake, Seasonal Sanctuary, Deep Dark Dungeon, Bowser in the Airship Armada, and the Challenge Mode hub.

Fourth Floor
Main Article: Princess Peach's Castle/Fourth Floor

The Fourth Floor never has a consistent way of accessing it. It is often claimed to be a large maze, though several reports have claimed it functions as an actual floor. It contains the Internal Garden, a garden area inside the castle, and the Toad Shrine, a large statue of a toad. It also contains Peach's Bedroom, a self-explanatory area.

Castle Dungeon
Main Article: Princess Peach's Castle/Castle Dungeon

A sub-area of the Castle Basement, the Castle Dungeon leads to Fox Forest and Bully Beach.

Bowser's Domain
Main Article: Princess Peach's Castle/Bowser's Domain

Bowser's Domain is a hidden area that was first documented by youtuber Marionova64. Bowser's Domain is accessed by jumping past an invisible wall blocking people from accessing the Bowser painting in the hall that leads to Bowser in the Dark World, and falling through a second trapdoor. The area itself is a large maze. There are notable areas such as the starting room, Luigi room, mirror room and Koopa library. In the "Luigi room", there is a painting of Luigi that when entered, will unlock Luigi as a playable character. There is also a variation of the Bowser Room found inside.

Fifth Floor
Main Article: Princess Peach's Castle/Fifth Floor

The Fifth Floor is unlocked after clearing Dire, Dire Docks Village. It contains Burning Meteor, Dark Heaven 2, Robo Station Way, Stanley's Showdown and Reginald's Last Stand. It also has a room that leads to every village in the game except for Eternal Village.

Fifth Floor B
Main Article: Princess Peach's Castle/Fifth Floor B

Fifth Floor B is unlocked by collecting the star in Eternal Village. It only consistently contains Robo-Luigi.

Third Basement
Main Article: Princess Peach's Castle/Third Basement

The Third Basement functions as a Bowser level, with a boss fight against Dark Matter, the ally of Reginald.

Third Basement B
Main Article: Princess Peach's Castle/Third Basement B

An extension of the Third Basement with a star after some platforming.

Castle Garden
Main Article: Princess Peach's Castle/Castle Garden

A replacement of the Castle Courtyard.

Floor 2B
Main Article: Princess Peach's Castle/Floor 2B

Unlocked after getting a Big Boo's Key, it contains Toxic Cavern, Boiling Hot Basalt, Dry Bones Desert, the Switch Dungeon, and Bowser in the Randomized Realm. Notable rooms in it are the flooded hallway, and the block room, which leads to the Switch Dungeon.

Elevator Room
Main Article: Princess Peach's Castle/Elevator Room

An elevator that can take you to any floor you've unlocked.

Goomba Courtyard
Main Article: Princess Peach's Castle/Goomba Courtyard

A replacement of the Castle Courtyard, found by jumping over a fence in the Castle Grounds. It is filled with Goombas.

Hotel Floor
Main Article: Princess Peach's Castle/Hotel Floor

A floor after the Fifth Floor, designed like a hotel.

Bowser's Castle
Main Article: Bowser's Castle

Bowser's Castle is the name of a supposed new variant of Princess Peach's Castle found after a Bad Ending.

Moon Courtyard
Main Article: Princess Peach's Castle/Moon Courtyard

The Moon Courtyard is a replacement of the Castle Courtyard with collectible moons, similar to those of Super Mario Odyssey.

Internal Plexus Theory
The Internal Plexus Theory states that Princess Peach's Castle is the veins of the Personalization A.I. People justify this theory with the layout of the castle being strange, as rooms should overlap and stretch out of the castle, though they do not, and that the areas inside the castle walls look strange and unsettling.