Unrevisitable area

Unrevisitable locations are locations in Mario games that are inaccessible after a certain point. Unrevisitable locations are primarily found in Mario RPGs where the player is automatically taken to such locations during the storyline and may contain items. Several platformer games that allow the player to roam on world maps may contain levels that can only be accessed once on the world map, or near the beginning of the game. For this reason, linear games are not included.

Super Mario World
The four switch palace levels, Yellow Switch Palace, Green Switch Palace, Red Switch Palace and Blue Switch Palace, cannot be accessed after the player steps on the respective switches. Castle levels cannot be reentered again unless the player holds both and  at the same time.

Super Mario Land 2: 6 Golden Coins
Stages containing bosses cannot be accessed again after defeating the respective bosses in each zone.

Wario Land: Super Mario Land 3
Course 10 in Mt. Teapot is replaced with Course 13, an altered version of itself, once the player hits the giant ! Block in Course 12.

Super Mario World 2: Yoshi's Island
The tutorial level Welcome to Yoshi's Island cannot be revisited again after completing the level or exiting it from the menu. In Yoshi's Island: Super Mario Advance 3, however, this level appears again at the end of the secret stage Endless World of Yoshis.

Super Mario RPG: Legend of the Seven Stars
Bowser's Keep is locked out for the majority of the game until Mario's party can visit it again via the Royal Bus. The layout of Bowser's Keep is replaced with an extended version upon this second visit. The player can no longer visit Count Down's room in Factory after defeating it.

Paper Mario
After defeating the Koopa Bros., the large jail cell where Mario meets Bombette has its hole patched up and the player cannot revisit it. After defeating Fuzzipede, the player can no longer navigate inside the whale's body. After the eruption of Mt. Lavalava, the bottom of the room just before Lava Piranha's becomes unsuitable for Mario to walk on, preventing the player from accessing the chambers beyond. Madam Merlar's cavern in Shiver Mountain becomes inaccessible after placing the Star Stone in the pedestal outside, causing flights of stairs to rise up and block the entrance.

Paper Mario: The Thousand Year Door
The Black Skull cannot be entered inside once Flavio hands the Skull Gem to Cortez. The storage cabin and the rooftops of the Excess Express cannot be revisited after defeating Smorg.

In the Palace of Shadow is a hidden room connected to Gloomtail's chamber that can be accessed by blowing up a wall with Bobbery, which contains a Jammin' Jelly and an Ultra Shroom. Once the player places the Star Key in the pedestal in the Riddle Tower, the floors of the four hallways leading to Gloomtail's chamber become stairs, preventing the player from accessing these rooms.

Mario & Luigi: Superstar Saga
The player cannot revisit Princess Peach's Castle after talking to Bowser to leave for the Beanbean Kingdom. The player can access the Koopa Cruiser only twice: the first visit just before reaching the front of the ship and battling Fawful; the second visit after Joke's End where Luigi navigates through the ship in reverse order before collecting the Beanstar. The Mushroom Kingdom side of Stardust Fields is not accessible after crossing the border to the Beanbean Kingdom. The underground caverns beneath Chucklehuck Woods after defeating Chuckolator cannot be revisited after Luigi interacts with the barrel with Mario inside it. The player cannot revisit Guffawha Ruins after Luigi collects the Crabbie Grass. The S.S. Chuckola cannot be revisited once it heads out to sea and sinks in the Oho Ocean Seabed. The player cannot revisit the caverns where the Jellyfish Sisters teach the Mario Bros. their techniques after collecting both Pearl Beans.

Puzzle & Dragons: Super Mario Bros. Edition
After defeating Bowser in, the player faces him again with the Koopalings in a multicolored void for the final battle. Once Bowser joins the player's team, the latter area cannot be revisited.