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
Continuing historic surveys and inventories of the area found that the blocks between the Ten Broeck Triangle and North Swan also had many intact rowhouses from the same 19th century period with little modern intrusion, even if some of them were in a state of neglect and disrepair. That area also extended to St. Joseph's School, part of the church's complex. Accordingly, in 1984, the district was extended by to its present size. In addition to almost tripling its area, it more than doubled the amount of contributing properties. The expanded district was renamed to reflect the area's wider scope and historic naming.