Pipeline is a multiplayer map in Call of Duty 4: Modern Warfare designed around two large warehouses that are beside each other. It is a map favoured by snipers due to the abundance of long sight lines and cover. The map is set in Russia, and also features a train track. There is a well known glitch known as the "pipeline glitch" that allows the player to go underground and actually wander the pipes. This level is only available on the multiplayer games. This is a great level for getting hiding places to then use your sniper against the other enemies.