Mount Chiliad is the largest mountain in San Andreas, located on the north western part of the island.
A major mystery surrounds the mountain, starting with a mural painted on the wall of the lift station at the mountain's peak. Glyphs can be found on the side of the mountain that seem to be instructions, leading the player to seeing a UFO while standing on the viewing platform at the mountain's peak at 3 AM while it's raining. (This requires 100% game completion)
Mount Chiliad is the largest and tallest mountain located in the game. It is located at the top end of the game map above the Alamo Sea, and below Paleto Bay. It occupies a large majority of the top of the map, and is nearly impossible to miss ingame.
A lift station in Paleto Bay can take you to its peak.
At the peak of the mountain is a viewing platform with two telescopes, and a board depicting southern San Andreas.
On the back side of the platform, the words "Come back when your story is complete" can be found. This is referring to the 100% completion requirement in order to see any of the UFOs .
- Main article: Mural
On the side of the mountain, boxes with X's are drawn with lines connecting them. On the bottom, three squares are drawn with what appear to be a UFO, an egg with a crack in it, and a stick figure with a jetpack .
- Main article: Glyphs
A total of 5 glyphs have been found on the side of Mount Chiliad. These glyphs seem to be instructions for how to get the UFO to appear at night in the rain, but two of the glyphs have unknown meanings.
This glyph shows a picture of a rain cloud below an eye/UFO.
This glyph depicts a crescent moon below an eye/UFO, with three vertical dashes between them. It's assumed that the crescent moon stands for night, and the 3 dashes stand for 3 AM, which are both requirements to see the UFO at the mountain's peak.
It's also possible that the glyph is an instruction relating to the phases of the moon, but that has yet to be proven.
This glyph shows what seems to be a mountain, probably Mount Chiliad, with a zig-zagging path leading to its peak. At the top is a small box, which seems to be the lift station.
It's also possible that the glyph is depicting Mount Gordo instead, as Mount Gordo has a zig-zagging path and also has a building on its peak.
The faded glyph is a plain eye/UFO with one side faded away. It looks like it's been worn away by the weather.
The meaning of this glyph is still unknown, but people have suggested it's referring to the Penris Building. No link has been found yet.
The 5th glyph to be found, the plain glyph is just an eye/UFO. There's nothing significant about it. Its meaning us unknown, as well.