The common was gradually reduced in size to its present roughly triangular shape, and surrounded by buildings in the 18th and 19th centuries.

[2] The district now includes properties across Waterhouse Street to the west of the common, including the Christian Science Church, a Classical Revival structure, the brick apartment houses along[clarification needed] and the 1753 Georgian Frost-Waterhouse House, the oldest building in the district.

To the north, across Massachusetts Avenue, the district includes Hemenway Gymnasium, Hastings Hall, Gannet House, and the Harvard-Epworth United Methodist Church.

On the south side, across Garden Street, lie the Old Burying Ground, The First Parish in Cambridge, Christ Church (a National Historic Landmark), and several houses.

It represents a well-preserved collection of properties dating to the 18th and 19th centuries that harken back to the days when Harvard Square was primarily residential in character.