In the south, is the city of Los Santos. To the west is the countryside, and in the north-west is San Fierro. The large gray area in the countryside is Mount Chiliad, which is notable for being the highest peak in the entire game. The city to the north is Las Venturas, and is separated from the Los Santos countryside by the sea, but can be accessed over several bridges. From Fierro, the only access point is the Gant Bridge.
Los Santos is heavily influenced by the real life city of Los Angeles, and is where the early part of Carl Johnson's story takes place. As well as being where the story begins, Los Santos is also where the story ends too. Los Santos contains different areas, such as a sprawling ghetto, residential areas, a financial district, and a rich area. The rich area of the city is split between Richman and Rodeo, though both areas house expensive clothing shops and fancy cars. Los Santos is also the area where most players will spend the majority of game time, at least until they complete the game. Not only this, but Los Santos is where four different gangs wage war, and below is the guide to each of the gangs:
Grove Street Families
The Grove Street Families are the gang that Carl "CJ" Johnson is part of. Along with Sweet, Big Smoke, and Ryder, they make up the lieutenants of the gang. The Grove Families were an alliance of different gangs around the area, until they split apart. The Grove Street Families, or GSF, wear green clothing.
The game's take on San Francisco. CJ's travels while trying to escape Officer Tenpenny take him here, where he starts a garage business with his sister Kendl, Ceasar, The Truth, and other accomplices. San Fierro features foggy weather, lots of tall buildings, hilly terrain, and an aircraft carrier near the docks, which holds several Hydra fighter jets.
The final destination in San Andreas, based on Las Vegas. The city features several casinos, and lots of eye-candy along "The Strip", where most of the city's attractions are found, as well as Las Venturas Airport.
A mountain to the west of Los Santos and to the south of San Fierro. Officer Tenpenny takes Carl's unconcious body to the nearby town of Angel Pine about a third through the game to do some dirt work, which involves climbing Mount Chiliad.
A top secret military base located to the west of Las Venturas, in the middle of the desert. Flying over this area in an aircraft will result in SAM (Surface-to-Air Missile) launchers being fired at you and Hydra fighter jets being scrambled to intercept you. The base contains army trucks, tanks, aircraft, a jetpack, and plenty of armed guards.