Portal takes place in the Enrichment Center for Aperture Laboratories—also known as Aperture Science—which is the fictional research corporation responsible for the creation of the portal gun. According to information presented in Portal 2, the location of the complex is in the Upper Peninsula of Michigan
. Information about the company, developed by Valve for creating the setting of the game, is revealed during the game and via the real-world promotional website. According to the Aperture Science Web site, Cave Johnson founded the company in 1953 for the sole purpose of making shower curtains for the U.S. military. However, after becoming mentally unstable from mercury poisoning in 1978, Johnson created a three-tier research and development plan to make his organization successful. The first two tiers, the Counter-Heimlich Maneuver (a maneuver designed to ensure choking) and the Take-A-Wish Foundation (a program to give the wishes of dying children to unrelated, entirely healthy adults), were commercial failures and led to an investigation of the company by the U.S. Senate. However, when the investigative committee heard of the success of the third tier, a man-sized ad-hoc quantum tunnel through physical space with possible applications as a shower curtain, it recessed permanently and gave Aperture Science an open-ended contract to continue its research. The development of GLaDOS, an artificially intelligent research assistant and disk-operating system, began in 1986 in response to Black Mesa's work on similar portal technology. A presentation seen during gameplay reveals that GLaDOS was also included in a proposed bid for de-icing fuel lines, incorporated as a fully functional disk-operation system that is arguably alive, unlike Black Mesa's proposal, which inhibits ice, nothing more. Roughly thirteen years later, work on GLaDOS was completed and the untested AI was activated during the company's first ever bring-your-daughter-to-work day in May 2000. Immediately after activation, the facility was flooded with deadly neurotoxin by the AI. Events of the first Half-Life game occur shortly thereafter, presumably leaving the facility forgotten by the outside world due to apocalyptic happenings. Wolpaw, in describing the ending of Portal 2, affirmed that the Combine invasion from Half-Life 2 occurred during Portal's events.
The areas of the Enrichment Center that Chell explores suggest that it is part of a massive research installation. At the time of events depicted in Portal, the facility seems to be long-deserted, although most of its equipment remains operational without human control. Aperture Science exists in the Half-Life universe, with the events of Portal occurring sometime between the story of Half-Life and Half-Life 2. Aperture Science Inc. is also mentioned during Half-Life 2: Episode Two, in which Aperture's icebreaker ship Borealis is said to have disappeared under mysterious circumstances, along with the crew and part of its drydock. During its development, Half-Life 2 featured a chapter set on the Borealis, but this was abandoned and removed before release.