MIT buildings all have a number and most have a name as well. Typically, academic and office buildings are referred to only by number while residence halls are referred to by name. A network of underground tunnels connects many of the buildings, providing protection from the Cambridge weather. Students agree that this maze is a welcome feature, enabling them to get from class to class without getting cold or wet. The bridge closest to MIT is the Harvard Bridge. It is the longest bridge crossing the Charles River. The bridge is marked off in the fanciful unit called the Smoot: 364.4 Smoots and One Ear. The Kendall MBTA Red Line station is located on the far northeastern edge of the campus. The neighborhood of MIT is a mixture of high tech companies seeded by MIT alumni combined with working class neighborhoods of Cambridge (see Kendall Square).

Early constructions

The most striking part of the campus is Killian Court, also known as the Great Court, in front of the Great Dome, where commencement is held (as well as the annual J. Edgar Hoover Memorial Celebration on May 2, for several years following his death on May 2, 1972), but most of the campus contains a jumble of different architectural styles which many accuse of lacking elegance. A few other buildings are architecturally significant, including Baker House (the dormitory designed by Alvar Aalto) and Eero Saarinen's Kresge Auditorium. The first buildings constructed on the Cambridge campus are known officially as the Maclaurin buildings, completed in 1916, after Institute president Richard Maclaurin who oversaw their construction; they surround Killian Court on three sides. On one side of Killian Court is the Infinite Corridor, which serves as something of a main artery for the campus, connecting east campus with west campus. The Infinite Corridor runs through two domes: the Great Dome, which is featured in most publicity shots, and the lesser dome (surmounting what is known as "Lobby 7" after its building number), which opens into Massachusetts Avenue, and which is the entrance most often used as well as the official address of the Institute as a whole. A shot of the Great Dome was used in a Star Trek episode to depict a generic building on a planet dominated by ancient Roman culture.

The Maclaurin buildings, in many ways the public "entrance" of MIT, were designed by Welles Bosworth based on plans developed by wealthy alumnus and hydraulic engineer John Ripley Freeman. Bosworth's design was drawn so as to admit large amounts of light through exceptionally large windows on the first and second floors, many internal windows—not only on office doors but above door-level, and skylights over huge stairwells. The interior decor of the Maclaurin buildings is stylistically consistent throughout. Its major architectural features are the Infinite Corridor, an impressive central dome, and the expansive domed lobby at the main 77 Massachusetts Ave. entrance. The friezes of these buildings are carved in large Roman letters with the names of Aristotle, Newton, Franklin, Pasteur, Lavoisier, Faraday, Archimedes, da Vinci, Darwin, and Copernicus; each of these names is surmounted by a cluster of appropriately related names in smaller letters. Lavoisier, for example, is placed in the company of Boyle, Cavendish, Priestley, Dalton, Gay Lussac, Berzelius, Woehler, Liebig, Bunsen, Mendelejeff [sic], Perkin, and van't Hoff.

I. M. Pei '40 designed a number of MIT buildings constructed in this period, including the Green Building (Building 54), headquarters of the Earth, Atmospheric, and Planetary Science Department and the tallest building on campus; Building 66, the Chemical Engineering Department; and the Weisner Building (Building E15), the Media Laboratory, whose tiled exterior was designed by Kenneth Noland.

Recent building efforts

A major building effort has been underway for several years (as of 2005), including the Simmons Hall dormitory (designed by Steven Holl), the Zesiger sports and fitness center, and a new home for the Picower Center for Learning and Memory, the Department of Brain and Cognitive Science, and the McGovern Institute for Brain Research (designed by Charles Correa).

The Frank Gehry-designed Stata Center opened in March, 2004. Boston Globe architecture columnist Robert Campbell wrote a glowing appraisal of the building on April 25th. According to Campbell, "the Stata is always going to look unfinished. It also looks as if it's about to collapse. Columns tilt at scary angles. Walls teeter, swerve, and collide in random curves and angles. Materials change wherever you look: brick, mirror-surface steel, brushed aluminum, brightly colored paint, corrugated metal. Everything looks improvised, as if thrown up at the last moment. That's the point. The Stata's appearance is a metaphor for the freedom, daring, and creativity of the research that's supposed to occur inside it." Campbell stated that the cost overruns and delays in completion of the Stata Center are of no more importance than similar problems associated with the building of St. Paul's Cathedral. The 2005 Kaplan/Newsweek guide "How to Get into College" , which lists twenty-five universities its editors consider notable in some respect, recognizes MIT as having the "hottest architecture", placing most of its emphasis on the Stata Center.

The building of the Stata Center necessitated the removal of the much-beloved Building 20 in 1998. Building 20 was erected hastily during World War II as a temporary building that housed the historic Radiation Laboratory. Over the course of fifty-five years, its "temporary" nature allowed research groups to have more space, and to make more creative use of that space, than was possible in more respectable buildings. Simson Garfinkel quoted Professor Jerome Y. Lettvin as saying "You might regard it as the womb of the Institute. It is kind of messy, but by God it is procreative!"