The Mount Chiliad Mystery is a myth in GTA V that refers to a series of mysterious markings scattered around Mount Chiliad, the largest mountain in San Andreas.
Description
The wall marking at cable car station.
Inside the cable car station at the summit of the mountain is a large map hanging on a wall that appears to be a map of Mount Chiliad. Scattered across the map are various odd symbols, seemingly pointing out the locations of secret objects on Mount Chiliad.
A strange symbol can be seen drawn above Mount Chiliad on the map. The symbol appears to be an eye. This symbol is called the Eye of Providence, also known as the All Seeing Eye, which could be a reference to the Illuminati.
Another strange symbol can be found marked in red underneath the viewing platform. This is believed to be related to the achievement From Beyond the Stars where some UFO parts must be collected, as it shows what appears to be the map of GTA V with some markers on it. The last drawing is etched behind the viewing platform that reads "Come back when your story is complete". If the player returns to Mount Chiliad after getting 100% Completion, a UFO will appear floating in mid-air above Mount Chiliad. This has been proven to be an Easter Egg.
These "Easter Eggs" may also be a reference to the Illuminati, an old secret society. In the Illuminati, there is a symbol called the "All Seeing Eye", which is an eyeball placed onto a pyramid. This may be what the drawing inside the cable car might be, but Mount Chiliad is the pyramid. The strange red mark also bears a resemblance to an eye, and "Come back when your story is complete" could be a reference to the New World Order, the Illuminati's scheme to take over the world and make 1 totalitarian government.
Solving the Mystery
The mystery behind UFOs, the Underwater Hatch and the possibility of a jetpack in the game may be on the verge of being solved. On the Map: #1 is where the Sunken UFO Wreckage is located. #2 is a marking of a hatching egg, which in the Epsilon Cult is said the world hatched from an egg. So another underwater hatch could be here or something else. #3 is a marking of a person wearing a jetpack, which has yet to be found in the game. This location is where the military base Fort Zancudo is, which would be the most likely place to discover a jetpack since in GTA San Andreas the military base Area 69 had a jetpack. The central part of the pyramid on the map is where the UFO at Mount Chiliad is located. The stars on the map are where the other strange markings can be found. Since the pyramid chart is divided into 6 sections, with 3 having markings, there may be 3 more undiscovered markings left which might be enough to solve the mystery. It's also no coincidence that there are All Seeing Eyes scattered throughout the map which is a clue to this pyramid chart. Also looking at the map of San Andreas a clear resemblance between the markings on the cable car and the northern/Mount Chiliad section can be seen. Some 'unconfirmed' reports mention finding a jetpack in Grapeseed county. This can be seen on the chart by placing the all seeing eye at the Paleto Bay area (which sticks out the top of the chiliad area) and if you follow the highway from Paleto Bay (through Mount Chiliad and Mount Gordo) to Grapeseed a resemblance can be made between the line on the left side of the pyramid and said highway. Referring to the markings and the Chiliad area the hatching egg may be in the Alamo Sea and the UFO may be over Chiliad Wilderness. Some believe the map is tied to Mount Chilliad in GTA San Andreas, as there is a tunnel in that version.