Harvard–Smithsonian Center for Astrophysics

The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on astrophysical studies including galactic and extragalactic astronomy, cosmology, solar, earth and planetary sciences, theory and instrumentation, using observations at wavelengths from the highest energy gamma rays to the radio, along with gravitational waves. Established in Washington, D.C., in 1890, the SAO moved its headquarters in 1955 to Cambridge, Massachusetts, where its research is a collaboration with the Harvard College Observatory (HCO) and the Harvard University Department of Astronomy. In 1973, the Smithsonian and Harvard formalized the collaboration as the Center for Astrophysics | Harvard & Smithsonian (CfA) under a single Director.

The Sears Tower—Harvard Observatory is a historic astronomical observatory that is part of Harvard Observatory and is located at 60 Garden Street in Cambridge, Massachusetts. Now just a portion of the observatory's Building A, the Sears Tower is the oldest portion of the complex, designed by Isaiah Rogers and constructed in 1843. This structure is a square brick building, with a projecting cornice and a Greek Revival entrance framed by pilasters. The dome was equipped with a 15-inch telescope, the state of the art at the time.The tower was listed on the National Register of Historic Places in 1987.

The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United States, and was founded in 1839. With the Smithsonian Astrophysical Observatory, it forms part of the Harvard–Smithsonian Center for Astrophysics. HCO houses a collection of approximately 500,000 astronomical plates taken between the mid-1880s and 1989 (with a gap from 1953–1968). This 100-year coverage is a unique resource for studying temporal variations in the universe. The Digital Access to a Sky Century @ Harvard project is digitally scanning and archiving these photographic plates.

The 1.2 meter Millimeter-Wave Telescope at the Harvard-Smithsonian Center for Astrophysics and its twin instrument at CTIO in Chile have been studying the distribution and properties of molecular clouds in our galaxy and its nearest neighbours since the 1970s. The telescope is nicknamed "The Mini" because of its unusually small size. At the time it was built, it was the smallest radio telescope in the world. Together, "The Mini" and its twin in Chile have obtained what is by far the most extensive, uniform, and widely used galactic survey of interstellar carbon monoxide. "The Mini" is currently in operation from October to May each year.In the early 1970s, an astronomer at the Goddard Institute of Space Studies in New York named Patrick Thaddeus shattered centuries of precedent in the field of astronomy and bucked a trend dating all the way back to Galileo when he decided that, in order to proceed on a modest project to map the entire Milky Way, he simply did not need and in fact refused to use a larger telescope made available for his research. He wanted a small one. In an era made conspicuous by bigger, more sophisticated, and more expensive telescopes, Thaddeus insisted on a small and relatively inexpensive instrument, which he and his colleagues proceeded to build from scratch.

The Asa Gray House, recorded in an HABS survey as the Garden House, is a historic house at 88 Garden Street, Cambridge, Massachusetts. A National Historic Landmark, it is notable architecturally as the earliest known work of the designer and architect Ithiel Town, and historically as the residence of several Harvard College luminaries. Its most notable occupant was Asa Gray (1810–88), a leading botanist who published the first complete work on American flora, and was a vigorous defender of the Darwinian theory of evolution.

Hall Tavern is an historic tavern at 20 Gray Gardens West Street in Cambridge, Massachusetts. Now converted to residential use, this two story Federal style wood-frame building was built in sometime in the late 1790s in Duxbury, Massachusetts, and was moved to this location in 1930. The building is one of a number that were moved in order to preserve them in the early decades of the 20th century, and it is now one of the centerpieces of the Gray Gardens subdivision.The building was listed on the National Register of Historic Places in 1983.

Harvard University Press (HUP) is a publishing house established on January 13, 1913, as a division of Harvard University, and focused on academic publishing. It is a member of the Association of American University Presses. After the retirement of William P. Sisler in 2017, the university appointed as Director George Andreou.The press maintains offices in Cambridge, Massachusetts near Harvard Square, and in London, England. The press co-founded the distributor TriLiteral LLC with MIT Press and Yale University Press. TriLiteral was sold to LSC Communications in 2018.Notable authors published by HUP include Eudora Welty, Walter Benjamin, E. O. Wilson, John Rawls, Emily Dickinson, Stephen Jay Gould, Helen Vendler, Carol Gilligan, Amartya Sen, David Blight, Martha Nussbaum, and Thomas Piketty. The Display Room in Harvard Square, dedicated to selling HUP publications, closed on June 17, 2009.

The William Dean Howells House is a house built and occupied by American author William Dean Howells and family. It is located at 37 Concord Avenue, Cambridge, Massachusetts. The house was designed by Howell's wife, Elinor Mead, and occupied by the family from 1873 to 1878. Authors including Mark Twain, Henry James, Henry Wadsworth Longfellow, and Thomas Bailey Aldrich visited the Howells in this house, as did President James Garfield, and Helen Keller lived there afterwards while attending school.

The Gray Gardens East and West Historic District is a historic district encompassing an early 20th century residential subdivision in Cambridge, Massachusetts. The subdivision includes all of the properties on Gray Gardens (East and West), as well as the adjacent 91 Garden Street and 60 Raymond Street. The subdivision was created by a group of interested individuals who sought to control development of one of the last estates in the area to be developed. They subdivided the land themselves, and imposed architectural restrictions on what could be built. Most of the houses were built between 1922 and 1930 and are neo-Georgian in style; the principal exception is the Hall Tavern, a Federal style tavern built in the 1790s and moved to the area from Duxbury, Massachusetts. The other unusual house is at 16 Gray Gardens East; it is a Tudor Revival house.The district was listed on the National Register of Historic Places in 1986.

The Percy W. Bridgman House is an historic house at 10 Buckingham Place in Cambridge, Massachusetts, United States. It is a National Historic Landmark, notable for its associations with Dr. Percy Williams Bridgman, a physicist, Nobel Prize winner, and Harvard University professor. It is now part of the Buckingham Browne & Nichols (BBN) Lower School campus.The house is an architecturally undistinguished 21⁄2 story house built about 1920 in a Neo-Rationalist style. At the time of its designation as a National Historic Landmark in 1975, the house had not been significantly altered since Dr. Bridgman's death in 1961. It was acquired by the BBN School not long after his death, which has used it for a variety of purposes, including as a faculty residence and lounge. It is used for school offices. Percy Bridgman (1882–1961) was born in Cambridge, raised in Newton, and educated at Harvard. After receiving his Ph.D. in physics in 1908, he was invited to join the Harvard physics faculty, where he remained for the rest of his life. Bridgman's primary area of research was high pressure physics. He was awarded the Nobel Prize in Physics (the fifth American to be so honored) in 1946 for his development of equipment for advancing research in that field. He also wrote extensively on the epistemology of physics and the sciences, advancing an idea that became known as operationalism, the view that the concept underlying any measurement was synonymous with a corresponding set of operations performed in making the measurement. Bridgman moved into this house in 1928, and lived there for the rest of his life.

The Col. Thomas Wentworth Higginson House is a historic house in Cambridge, Massachusetts. It is named after author, minister, and abolitionist Thomas Wentworth Higginson, who had it built and lived there for a time.The house was built in 1880 and added to the National Register of Historic Places in 1982. It was the first home that Higginson ever owned. As he wrote to his sister shortly after moving in, "It is such inexpressible happiness to have at last a permanent home."

Neighborhood Nine, also known as Peabody or Area 9, is a neighborhood of Cambridge, Massachusetts, U.S. It is mostly residential.