Arbor Hill Historic District–Ten Broeck Triangle
Open space within the district include a few vacant lots and parking lots. Most are planned however, such as Van Rensselaer Park, the neighboring space around the church known as St. Joseph's park, and the large parcel at the district's northeast corner where the Ten Broeck Mansion and its gardens (and formerly carriage house) are located. Mature trees are abundant throughout. Topographically the district rises almost a hundred feet (30 m) from its eastern and southern edges to level terrain along North Swan between Second and Third. This reflects the ravines that existed there when Albany was first settled, later partially filled in to facilitate development, now the neighborhood of Sheridan Hollow, which separates Arbor Hill and the district from downtown Albany.
Arbor Hill Historic District–Ten Broeck Triangle
The future district was first established by its oldest contributing property, the Ten Broeck Mansion, built at the end of the 18th century by a prominent local family. It lent its name to the Ten Broeck Triangle, established in the middle of the following century when successful businessmen, primarily lumber dealers, built large houses along Ten Broeck Avenue with the fortunes they had made from trade on the Erie Canal. It was one of the first neighborhoods to develop north of the city's downtown as it grew during the 19th century.