Blue Hell is the name given to the area found underneath the landmass in all Grand Theft Auto games. The player is not supposed to enter Blue Hell, but several game glitches can occur which will result in the player ending up there. When the player enters Blue Hell, they will fall for a few seconds before respawning on the nearest "solid" landmass.
Blue Hell is comprised of a bottomless pit, and there are several "entrances" (though they may vary for each game), though these "entrances" are most likely overlooked glitches in the game and not intended to be there.
- In Esplanade North, San Fierro, the player can find several docks strutting out into the San Fierro Bay and warehouses situated on them. Next to one of these docks is a submarine called the "U.S.S. Numnutz". If the player swims directly down from the submarine to the bottom of the waterway next to the dock, they will notice a greyish color that does not match the color or texture of the surrounding rock. The greyish area is actually a hole that the player can swim through and enter Blue Hell.
- Also in San Fierro, there is a large clothing store in Doherty, opposite the tract of wasteland. The top portion of wall, between the top floor and roof, is not solid and allows entry if used in a jetpack.
- In Mulholland, Los Santos, there is a newspaper shop with a roof which is not entirely solid. If the correct place is found, the player can drop through to the interior of the building and from there blue hell itself.
- At Las Venturas Airport, one of the walls of the main building has a glitch wherein running at it enough will pop the player out into blue hell. The wall is located where the fence around the runway meets the building.
- Also in Las Venturas, but this time at the Come-A-Lot district, there is an unmarked Pay 'n' Spray east of the casino. The southwest corner of the Pay 'n' Spray is not solid. If the player goes into that spot, he will fall inside Blue Hell, later automatically spawning outside the Pay 'n' Spray, just along the sidewalk. The only way to enter Blue Hell through this means is to have a jetpack equipped, and let yourself sink on that hole for a while. You will find out that you are then under the surface.
- In The Atrium hotel lobby. If the player leaves the lobby, aims a gun and quickly walks backwards they will be able to make it through the door and inside the hollow shell of the building, without being warped into the "heaven" of the actual lobby. Though the first couple of meters of floor are solid, after this the floor is simply texture, and can be fallen through.
- Inside the Lil' Probe'Inn, in the room with the map of San Andreas, if the player turns his back on the map and keeps jumping on the boxes at the other side of the room, he can fall into Blue Hell and finds himself on the top of the bar. In this case, the player can get back to the "real world" by jumping from the top of the bar, as he will fall inside it again.