Pipeline is a gloomy setting centered around an abandoned rail yard in Ukraine, with a large extent of overgrown grassland. There are two large warehouses in the center of the map which often sees the main concentration of fighting. The north warehouse has a small room players can hide in and ladders leading to a catwalk which grants access to the roof. The south warehouse has a u-shaped upper level looking over the ground floor and office rooms. Additionally there is a entrance to an underground tunnel. This tunnel leads to the north-west and north-east sections of the map.
This map's layout supports a variety of play-styles, with the warehouses and tunnel encouraging frantic close-quarters action and the surrounding areas supporting mid to long-range action.
In the mission "One Shot, One Kill", buildings resembling the warehouses in this map can be seen.
In Call of Duty 2, one of the early missions involves the player crawling through a pipe at the beginning of the level. When they crawl through completely, they end up in what appears to be Warehouse 2 of this map. It is almost identical, with the small passageway that runs under the whole level present in the Call of Duty 2 version. The same warehouse-building returned even in Modern Warfare 3 in the single player mission "Back on the Grid" and the Spec-Ops mission "Fatal Extraction", although slightly modified.