In Pokémon games, an unrevisitable location is any location which is permanently inaccessible after a certain point. Unrevisitable locations are typically made accessible at one time or another due to the flow of the story of the game in which they are present in and may contain items or other content that can be permanently missed.
Locations that are temporarily unrevisitable, such as Steam Cave in the Pokémon Mystery Dungeon Explorers games, but are later permanently unlocked, are not included here.
In the core series[]
In Pokémon Ruby Version and Pokémon Sapphire Version and Pokémon Emerald Version, the Team Magma Hideout or Team Aqua Hideout is sealed off after the player defeats Tate and Liza and cannot be visited again beyond that point. This means that any items inside the hideout, most notably the Master Ball, can be permanently missed if the player did not collect them while the location was still accessible.
In all Kanto games, the SS Anne is a one-time location; once it departs from Vermilion Harbor, it can never be accessed again under normal gameplay; however, in Generation I, there is a glitch that allows the player to revisit the SS Anne.
In Pokémon Black Version and Pokémon White Version, the player cannot access N's Castle after defeating Ghetsis.
In Pokémon X and Pokémon Y, the player cannot access Team Flare Secret HQ after winning the final fight against Lysandre, as the building is destroyed.
In Pokémon Sword and Pokémon Shield, although the gyms (stadiums) can be freely revisited, the actual rooms where the player faces their gym challenges cannot.
In spinoff games[]
Pokémon Mystery Dungeon series[]
In Pokémon Mystery Dungeon: Explorers of Time and Pokémon Mystery Dungeon: Explorers of Darkness and Pokémon Mystery Dungeon: Explorers of Sky, although Craggy Coast, Mt. Horn, and Foggy Forest can be revisited, their optional counterparts (Side Path, Rock Path, and Forest Path, respectively) cannot. After the player, partner, and Grovyle return to the present after traveling through the time passage with the help of Celebi, Chasm Cave, Dark Hill, Sealed Ruin, Dusk Forest, and Deep Dusk Forest all become inaccessible and can never be revisited again, as these dungeons exist only in the future due to the planet's paralysis. The Nightmare is also a one-time dungeon; after clearing it, the dungeon cannot be revisited, likely due to it being a dream and thus existing only temporarily, rather than a physical location like most dungeons are. Fortunately, the music themes in those locations can be heard in other locations. For example, Chasm Cave shares its music with Spacial Rift, while Sealed Ruin shares its music with Deep Spacial Rift. Other themes serve as random themes for dungeons with rotating music themes; for example, Dusk Forest's theme sometimes plays at Midnight Forest.
In several storyline dungeons in the Explorers games, such as Craggy Coast, Mt. Horn, and Treeshroud Forest, the storyline visit (first visit) grants the player a rest area that allows the player to move about near the entrance and save their game using a Kangaskhan Rock. None of these rest areas are revisitable. This does not apply to mid-dungeon rest areas, called "relay points", which are revisitable on all visits, as long as the dungeon itself is revisitable.
The cutscene right after defeating Groudon in Chapter 9 is the only time Fogbound Lake can be visited. After the cutscene ends, the player can never visit Fogbound Lake again. All subsequent successful visits to Steam Cave end at Steam Cave Peak instead.