This is a '''list of minor Black Mesa locations''' featured in ''Half-Life'' and its Half-Life expansions|expansions.
==Black Mesa South Access Tunnel==
The Black Mesa South Access is a location featured in ''Half-Life Blue Shift|Blue Shift'' in the chapter ''Deliverance''. It appears to be an entrance to the facility. Barney Calhoun and his friends teleport here to escape from the facility.
FileSouth Access Tunnel.jpg
==Unnamed Decay location==
This location is featured in ''Half-Life Decay|Decay'' in the mission ''Resonance''. It is a medium-sized facility near the surface level, and it contains the dampening locks. The players are sent here to reset the dampening locks to prevent another cascade from happening. There are two secondary locks upstairs, and one primary lock near a transit line. The starting area slightly resembles the test chamber from ''Half-Life'', so it may be the upper section of that room.
==Hydrofauna Studies Laboratory==
The Hydrofauna Studies Laboratory is a location featured in ''Half-Life Opposing Force|Opposing Force'' in the chapter ''Crush Depth''. It contains a series of underwater laboratories where aquatic alien creatures are kept and observed, as well as teleporters.
This location is featured in ''Opposing Force'' in the chapter ''"The Package"'', and in ''Decay'' in the bonus mission ''Xen Attacks''. It is a large underground parking garage, and is connected to a series of train tunnels. The Black Ops assassins plant a Mark IV Thermonuclear Device|bomb here to destroy the entire facility. The bomb is disarmed by Adrian Shephard and rearmed by the The G-Man|G-Man. This leads to ultimate destruction of the facility. Two Vortigaunts are also sent here earlier by the Nihilanth to retrieve Crystal (Xen)|crystal samples.
FileSuv shock trooper.jpg
FileG-Man bomb activate.jpg
==Level 4 Storage Unit==
The Level 4 Storage Unit is a location featured in ''Opposing Force'' in the chapter ''Worlds Collide''. It is a large basement storage area located under a parking garage. It is told the area was used by the Black Ops as a staging point until the aliens came in. The Race X also uses a sub area below to open a portal to bring in the Gene Worm.
FileGene Worm portal.jpg
FileGene Worm enters.jpg
CategoryLocationsCategoryHalf-LifeCategoryHalf-Life Opposing ForceCategoryHalf-Life Blue ShiftCategoryHalf-Life Decay