Where is the two-player mode on "GTA San Andreas" for the PS2?

The two-player mode in "Grand Theft Auto: San Andreas" can only be activated at certain specific points throughout the map. These points are marked with a red icon showing two figures.

The two-player missions come in two forms: Free Roam and Rampage. Free Roam icons can be found in five locations throughout the game world, and there are additionally five Rampages in which two players can participate. Each of these missions will restrict the second player to a handful of character choices drawn from the surrounding area. This mode is only found in the PlayStation 2 version of the game.