The Cordillera is a large mountain range and a mythical location that makes up the majority of the landmass in the northern reaches of Grand Theft Auto: San Andreas just North of the Gant Bridge and San Fierro.
The mountain range starts from the coast of Bayside and lasts to the western portion of Bone County until it starts to drop off at Las Venturas. While the area itself remains unnamed in-game and is not featured prominently in any missions, the Cordillera is a place of interest for people of all play styles, having great possibilities for offroading, photography, and more. Based on it's located the mountains are based off the Marin Headlands, a large mountainous region North of San Francisco.
After the game's release, the area soon caught the attention of myth hunters. The mountain range is extremely inaccessible, with multiple steep cliff-sides, some of which almost border a 90-degree angle.
Despite being in the semi-arid region of Tierra Robada and only having minor patches of grass at the bottom of the mountain, the Cordillera features many of the large redwood trees typically associated with the countryside of Flint County. The complete isolation from society and a large number of redwood trees have caused the Cordillera to be an epicenter for myth sightings, including Bigfoot and Woods Creature.
Another oddity that most players notice are red hazard lamps installed at the peaks of the mountain. The lamps are meant to guide aircraft so they don't crash into the mountains but due to how isolated The Cordillera is and the fact the taller Mount Chiliad has no lamps makes it seem all the more strange.