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
By 1870, much of the district had been developed. The lavish houses in particular that lined Ten Broeck Street gave it the popular name of "Millionaire's Row." Many had been built by lumber merchants and overlooked the Lumber District, the yards down by the canal and river where they did their business. Another church, Sweet Pilgrim Baptist, was constructed in 1876 at the Clinton Avenue intersection, giving the district a distinctive southern gateway. At the north corner, the polygonal home at 105 Ten Broeck featured an iron mansard roof, a hallmark of the contemporary Second Empire style. Some of the existing houses, such as 8 Hall Place, also had mansard roofs added when they were expanded with third stories.