City Hall Plaza in Boston, Massachusetts, is a large, open, unadorned public space in the Government Center area of the city. The architectural firm Kallmann McKinnell & Knowles designed the plaza in 1962 to accompany Boston's new City Hall building. The multi-level, irregularly shaped plaza consists of red brick and concrete. The Government Center MBTA station is located beneath the plaza; its entrance is at the southwest corner of the plaza.
The siting of the plaza, the City Hall, and other structures in Government Center was the responsibility of I. M. Pei, commissioned by Edward J. Logue, then development administrator of the Boston Redevelopment Authority. The plaza and City Hall were constructed between 1963 and 1968, on the former site of Scollay Square, which despite its vibrancy and historical interest, was considered a seedy area by some people. Other streets removed to make way for the plaza included Brattle Street and Cornhill.
The 1962 design was reportedly modeled after Piazza del Campo in Siena, Italy.
Reaction to the plaza has been mixed. Some praise City Hall Plaza for being cleaner and more appealing than Scollay Square, and for the simple fact that it was built at all—with the cooperation and compromises necessary of any complex, multi-agency government construction project. Architecture critic Ada Louise Huxtable called the plaza "one of the best urban spaces of the 20th century. ... With the plaza, and specifically because of it, the Boston Government Center can now take its place among the world's great city spaces." The Cultural Landscape Foundation listed the plaza as one of its "Marvels of Modernism."