Test cells are locations included within the game's files but are located outside the main world map. In Fallout 3, there are 29 test cells in the base game, with an additional 10 in Operation: Anchorage, 10 in The Pitt, 12 in Point Lookout, 2 in Broken Steel, and 17 in Mothership Zeta. Operation: Anchorage also contains a unique test worldspace, tLandscape, which contains an additional 9 conjoined test cells. This brings the total number of test cells for Fallout 3 and its add-ons to 89. There are also several empty test cells that exist the games files.