The Sky Door consists of two floating ENEX markers that hover high in the sky. ENEX markers are bouncing yellow arrows normally used to transport the player to hidden interiors when they walk into one. For instance the marker outside a gym "teleports" CJ into the gym's interior.
When entered, both sky doors transport the player to interiors named "Houses". The "Houses" are similar to those in the burglary side-mission, because there are items CJ can pick up including televisions and microwaves. There is a man in one "House" who is automatically hostile to the player, and when killed, his body doesn't produce blood.
As the name would suggest, the sky doors are located in Fort Carson. They are in a small corner of a fenced field across the road from the Cluckin' Bell restaurant, but high in the sky above the height limit.
It is possible to pass by the sky doors in the mission Stowaway, while Carl Johnson is parachuting from the Andromada. However, he cannot access them in this mission without cheats or mods. This is the only instance in which the player can actually see the sky door on an unmodded game, since it is normally above the game's height limit.
Entering the Sky Door
It is impossible to access the ENEX markers in normal gameplay because of two reasons:
- The sky doors don't have solid platforms under them. In order for CJ to enter a marker, he must be standing on a solid surface.
- The doors float above the height limit in the game. If the player attempts to fly an aircraft or jetpack past the limit they will simply not gain any height.
- 9mm Pistol (Interior #1)
- Knife (Interior #2)
- Skateboard (Interior #2, only available with mods, replaces knife pickup)
- Baseball bat (Interior #1)