The East Cambridge Historic District encompasses the historic center of East Cambridge, Massachusetts. This area was historically isolated from the rest of Cambridge by marshy land that was only filled in much later. The first organized development attempt, by the Lechmere Point Corporation, resulted in the layout of a rectilinear street grid in the area, the first in the Boston area. Major landmarks from the early years of its development are the 1827 Federal-style church at, built as a Congregational church and based on an Asher Benjamin design, and the Charles Bulfinch-designed county courthouse, which has been surrounded by complex of sympathetically-designed buildings. The district includes properties on Otis and Thorndike Streets between Fifth and Second Streets, plus portions of Spring, Sciarappa and Third Streets.