Announced at E3 2001, Princess Peach's Castle (ピーチ城, Peach Castle) is a stage in Super Smash Bros. Melee and returning in Super Smash Bros. Ultimate. It is the top of the castle as seen in Super Mario 64.
The level itself is comprised of three parts: The left side, the right side, and the middle. The right and left side are flat platforms with edges and a small floating stand that rises when a character stands on it. The middle section is comprised of two layers; the bottom layer is a risen, sloped platform with another similar platform on top. Occasionally, switches will appear somewhere on the castle. These switches are pressure activated, and come in three different colors: red, blue, and green. When a switch is activated, it makes some "!" Blocks and some platforms of the same color appear somewhere on the castle, and also applies about a full second of freeze frames to whatever touched it. Two Red "!" Blocks appear on either side of the castle roof, a sole Blue "!" Block appears at the top of the castle when its respective switch is stepped on, and two Green "!" Blocks appear bunched together on the far left side of the castle, suspended in the air. The blocks release items when one comes in contact with them, if items are on.
Every one to five minutes, a large Banzai Bill will shoot from the side of the stage in the sky. First there is the sound of a cannon firing, and then the Banzai Bill appears from a random side of the screen and goes in a slow straight path until it crashes into the castle. After approximately four seconds, it explodes and deals around 30-45 damage with very large knockback and results in a one-hit KO. Last hit can KO opponents at low percentage, if the opponent is being hit by the last hit instead of taking multiple hits. The last hit of the explosion (without taking multiple hits) is avoidable by DI'ing at 0%. The explosion is so strong that most fabrics (like Mario's cape or the flags on the stage) shake when it occurs. A possible tactic is to throw or hit an opponent into the explosion. The Banzai Bill itself also does light damage if touched before it explodes, and it has a similarly soft knockback. It is banned in tournaments due to walls (Shine infinite) and Banzai Bill interference but has been seen in much older tournaments.
This stage is from Super Mario 64. The overall design of the castle in this stage is very accurate to Princess Peach's castle seen in Super Mario 64; however, the very top spire is gone and the castle itself has been scaled down. Around the castle in Super Mario 64 can be seen a waterfall, some trees, a moat, and fences. This stage has all these features except now there is a flower bed in front of the castle. Behind the castle in Super Mario 64 is a courtyard that is filled with Boos. This courtyard and the boos are absent in this stage.
In Super Mario World there are these giant Bullet Bills called "Banzai Bills" that would shoot across the screen. Banzai Bills are seen in this stage being shot at the castle. They also dig themselves into the castle and explode, which is not like what they do in Super Mario World. Also in Super Mario World are these blocks that would appear once a switch is hit. The blocks have exclamation points on them. The switches are rounded at the top and has an exclamation point on them. There are also switches with exclamation points that make certain blocks appear in Super Mario 64. When the switch is hit it makes an item box appear. These item boxes also have exclamation points on them. The switches seen in this stage look like the switches seen in Super Mario 64 without the exclamation points. The item boxes that appear on this stage also look similar to the boxes in Super Mario 64. 
The music for this stage is a blend of both Super Mario Bros.'s above and underground theme. 
- Princess Peach's Castle
Princess Peach's magnificent royal castle appears to be inhabited solely by the princess and a multitude of Toads. Bowser tried to steal the castle's Power Stars in Super Mario 64, and in Paper Mario, the surly archfiend actually lifted the castle into the stratosphere with his own filthy fortress.
- There is a slight glitch with any AI character on this stage. Very rarely, when a Banzai Bill hits the center tower portion of the stage, the AI will try to head for the opposite edge of the stage to get away from the explosion. In doing so, however, it has been observed on at least one occasion that the character will actually jump into the blast in order to get to the other edge of the stage. This will, as with any incidence of a character caught in a Banzai Bill blast, result in a SD.