This unnamed Co-op Test Shaft featured in the cooperative campaign of Portal 2 is one of the nine Enrichment Shafts from the salt mines owned by Aperture Science Innovators, found underneath the computer-aided Enrichment Center. This test shaft had originally ran through cooperative testing during the vintage era, but was later utilized by GLaDOS after she gains more sight of the facility with previous help of ATLAS and P-body. It is featured within Test Course 5: Mobility Gels.