South Princeton Historic District is a three-block area of predominantly residential structures on South Hart, South Main, and West Water Streets just south of the courthouse square. It shows a broad range of architectural styles, with buildings ranging from the mid-nineteenth century to modern structures. Significant nineteenth century buildings include a c. 1860 Greek Revival house at 411 South Main Street, a Greek Revival/Italianate house and an Italianate house on South Hart Street, notable Queen Anne homes on South Hart Street and South Main Street, and a notable c. 1890 Romanesque Revival style First Presbyterian Church. The district also includes several outstanding twentieth century buildings representing a variety of styles, including notable American Four-Square and Bungalow style homes, two notable Colonial Revival style homes on South Hart Street, and a c.1930 Art Moderne gas station on South Main Street.