Potter–O'Brian House

The Newton Street Bridge is a historic bridge carrying Newton Street over the Charles River in Waltham, Massachusetts. The stone arch bridge was built in 1877 on the site of Waltham's first bridge, which was built c. 1761–62. It was designed by Hiram Blaisdell, a specialist in the design of masonry bridges. It consists of three elliptical arch segments on granite piers. The arches are formed of granite voussoirs, and the facing of the bridge is predominantly rough rock. It is the only 19th-century bridge in Waltham to escape significant alteration.The bridge was listed on the National Register of Historic Places in 1989.

The American Watch Tool Company is a historic factory complex at 169 Elm Street in Waltham, Massachusetts. The company was founded in 1877 as a spin-off from the successful American Watch Company, and was used for the production of watchmaking tools until 1904. The four-building complex traces the evolutionary history of this business. The factory was listed on the National Register of Historic Places in 1989.

The Waltham Gas and Electric Company Generating Plant is a historic power company generator building at 96 Pine Street in Waltham, Massachusetts. Built c. 1900–1909, this large concrete-and-stone building is an essentially unaltered early power generation plant, although all of its window openings have been filled with concrete. It originally housed a steam power generator, and was sold by Waltham Gas and Electric to Boston Edison, who converted it to an electrical substation in 1917, a role it continues to fulfill.The building was listed on the National Register of Historic Places in 1989.

The Waltham Gas Light Company was a historic industrial facility located at 2 Cooper Street in Waltham, Massachusetts. It was one of the oldest industrial complexes on the South Side of the city, with brick buildings dating to 1854–55, not long after the founding of the company. The Waltham Gas Light Company was founded in 1853 to provide natural gas for "illumination, fuel, and power" to the area. In 1886 the company added an electrical generation plant to the property, which lay in an area roughly bounded by the Charles River, the Boston & Maine railroad right-of-way, and Cooper Street, which now serves an access to the municipal parking garage just west of the company property. The company shut down in 1909, transferring its electrical business to Boston Edison, which still operates an electrical substation in a nearby former company building. The other company buildings were converted to other manufacturing uses, and were demolished in 2007.The complex was listed on the National Register of Historic Places in 1989, and has not been delisted since its demolition.

Boston Manufacturing Company Housing are historic residential housing blocks at 380–410 and 153–165 River Street in Waltham, Massachusetts. The housing was for the Boston Manufacturing Company (BMC), the earliest modern manufacturing facility in the United States. The housing was built in the nineteenth century and the two blocks of buildings were separately added to the National Register of Historic Places in 1989.

The Gilbrae Inn is a historic residential building in Waltham, Massachusetts. It was built as a two-story wood-frame structure by the Boston Manufacturing Company sometime between 1827 and 1854 as a boarding house for its workers. In c. 1870 the mansard roof and third floor were added. It is the only known surviving boarding house built by the company. Its name derives from a cloth pattern manufactured by the company.The building was listed on the National Register of Historic Places in 1989.

The Lawton Place Historic District is a historic district on Lawton Place between Amory Road and Jackson Street in Waltham, Massachusetts. The district preserves some of the nation's oldest textile mill worker housing. The duplex houses located on the south side of Lawton Place were built c. 1815-17 by the Boston Manufacturing Company (BMC), the first mill to process textiles entirely under one roof. They were originally located at what is now the Waltham Common, and were moved to Lawton Place in 1889. On the north side stands a rowhouse that was built in 1889; it is the last instance of a type of row housing that was once commonly built for mill workers. The district was listed on the National Register of Historic Places in 1989.

The St. Charles Borromeo Church is a historic Catholic church building in Waltham, Massachusetts. Built in 1922, it is a high quality example of Italian Renaissance Revival architecture, and is emblematic of the shift on Waltham's south side from a predominantly Protestant population to one of greater diversity. The building was listed on the National Register of Historic Places in 1989.

The John E. Olcott House is a historic house at 35–37 Central Street in Waltham, Massachusetts. Built c. 1837, the two story house is a rare local example of Federal style executed in brick. The house was built and occupied by John Olcott, a bricklayer, and is essentially vernacular in its styling, lacking some of the flourishes found in the more elaborate Elijah Fiske House. It is five bays wide, with a shallow-pitch hip roof, twin chimneys, and a projecting enclosed entry vestibule.The house was listed on the National Register of Historic Places in 1989.

The Leonard W. Stanley House is a historic house in Waltham, Massachusetts. The 2+1⁄2-story wood-frame house was built in 1855-56 by Leonard Stanley, a policeman. It is one of the oldest houses on the South Side of Waltham, which the city purchased from Newton in 1849, and is an unusual local example of transitional Federal/Italianate styling. Its basic massing is somewhat typically Federalist, with a five bay facade and side gable roof. However, it has deep eaves and segmented-arch attic windows, typical Italianate features. The main block was extended with ells in the 1870s and 1880s.The house was listed on the National Register of Historic Places in 1989.

The Richard Holbrook Houses are a pair of joined historic houses at 29 and 31 Heard Street in Waltham, Massachusetts. Both are 1+1⁄2-story Greek Revival cottages, that once had detailed styling, which has since been lost or sided over. The two houses were built in 1844 by Richard Holbrook, a housewright, and are rare surviving examples of a once-common form. The houses went through separate ownerships until 1892, when Patrick Welch acquired the second after acquiring the first in 1886. He was probably responsible for building the central connecting section.The houses were listed on the National Register of Historic Places in 1989.

The E. Sybbill Banks House is a historic house at 27 Appleton Street in Waltham, Massachusetts. Built in 1892, it is an excellent local example of vernacular Queen Anne styling. It was built for E. Sybbil Banks, the spinster daughter of Nathaniel Prentice Banks who was also a prominent local civil servant. The house was listed on the National Register of Historic Places in 1989.