City Hall Plaza, City Hall Plaza Tower or 900 Elm Street, is a prominent 275ft office tower in Manchester, New Hampshire. Since its completion in 1992, City Hall Plaza has been the tallest building in the city of Manchester, the state of New Hampshire, and northern New England . It is shorter than most of the tallest buildings in Boston, Hartford, New Haven, and Providence. The tower is used as office space for private businesses and for the Manchester city government.The building is recognizable as one of the main features of the Manchester skyline, along with the Brady Sullivan Plaza, SNHU Arena, the Radisson Hotel, the Center of New Hampshire, and the Amoskeag Bank building. The facade is brick and limestone, with a four-gabled blue roof.