Classic level included in latest patch from Valve, which also addresses a host of other issues.
Today, Valve Software has released the latest update for its popular multiplayer shooter, Counter-Strike: Source. The update, which will be automatically installed on PCs with the client program to Valve's Steam delivery service, includes the addition of the classic "Assault" map from the original Counter-Strike. Counter-Strike: Source is the original Counter-Strike remade with the new Source graphics engine, the basis of Half-Life 2. However, not all maps from the original game were updated.
News source: GameSpot