For over a decade, Grand Theft Auto V players have been curious about a secret underground alien facility hidden beneath Fort Zancudo, a piece of content Rockstar Games never included in the final game. Now, thanks to some dedicated modders, you can finally explore this eerie spot. The bunker’s packed with sci-fi goodies: alien bodies in glass tubes, a medical lab for extraterrestrial autopsies, and military-grade containment zones. It’s like something straight out of a conspiracy theorist’s notebook.
How Modders Revived the Lost Content
Last April, a leaked PlayStation 3 beta version of GTA V surfaced online, and data miners struck gold. They found files tied to the Mount Chiliad mystery, including references to this underground complex with three preserved alien bodies, a sterile autopsy room, and a massive hangar. One former Rockstar developer even suggested the Mount Chiliad mystery might’ve been a prank. The problem? The beta files were a wreck—no lighting, broken object collisions, stuck doors, and barely any textures. It was clear Rockstar abandoned this project halfway through and never revisited it, even for Grand Theft Auto Online.
Enter modder Antasurris and his team, who spent months reverse-engineering these PS3 files to work on modern PCs, with help from modder Transmet. They rebuilt large chunks of the bunker from scratch to make it playable. Some areas, like the main corridor and dissection lab, had more polish than others, with detailed textures and storytelling elements, as noted in a GTA Forums post.
Other parts, like the hangar, leaned heavily on reused assets from places like Humane Labs, suggesting Rockstar was just mocking up ideas. The alien tube room, for instance, has two of the three aliens stuck in an A-pose, and the room itself feels empty, likely never meant to be accessed by players. Despite the rough edges, the modders added sound, lighting, and fixes to make the Black Project: Zancudo Facility mod a coherent, explorable experience that stays true to Rockstar’s original concept. It’s now available as a free download for Grand Theft Auto V Legacy, Grand Theft Auto V Enhanced, and via FiveM on PC.
Rockstar’s Habit of Leaving Things Behind
Rockstar has a track record of scrapping content. Obbe Vermeij, a former Rockstar North tech lead, used to share details about cut ideas on his blog until it was taken down for revealing too much. Steven Ogg, Trevor Philips’ voice actor, also mentioned recording lines for a GTA V DLC that never happened. With Grand Theft Auto 6 set to launch on May 26, 2026, for PlayStation 5 and Xbox Series S/X after nearly a decade in development, it’ll be interesting to see what other abandoned content data miners uncover.
How to Get the Mod and Explore the Bunker
The Black Project: Zancudo Facility mod lets you dive into the bunker at its original beta coordinates, complete with a teleportation script, proper animations, and a mini-map. It even supports 12 languages. Here’s how to install it:
GTA V Legacy
- Extract the GTA V Legacy folder from the archive.
- Install the OIV with OpenIV (ensure OpenIV.asi and ScriptHookV are installed).
- Launch the game, head to the Fort Zancudo bunker, and explore!
GTA V Enhanced
- Extract the GTA V Enhanced folder from the archive.
- Install OpenRPF and the latest ScriptHookV.
- Drop the spblackproject folder into mods/update/x64/dlcpacks and blackproject.asi into your game directory.
- Add spblackproject to your dlclist.xml in mods/update/update.rpf/common/data.
- Replace the doortuning.ymt in mods/update/update.rpf/x64/levels/gta5 with the provided file.
- Launch the game, head to the Fort Zancudo bunker, and enjoy!
FiveM
- Extract the FiveM folder from the archive.
- Place its contents in your server’s resources folder.
- Launch the game and explore! (Note: The script isn’t included for FiveM, but you can create your own.)
Big shoutout to the modding community for pulling this off! It’s awesome to see fans breathe new life into Rockstar’s forgotten ideas. Will you be checking out the bunker? Let us know!