Chestnut Hill has been recognized as an architecturally important and intact historic neighborhood displaying the results of early subdivision plans and development spanning more than a century. In 1986, the Old Chestnut Hill Historic District was listed on the National Register of Historic Places (it was later expanded in 1990), clearly acknowledging the historical significance and architectural integrity of the District. The National Register Nomination describes the District as having commodious architect-designed houses with attention to landscape detail. The Chestnut Hill Historic District consists almost entirely of residential structures, most dating from the late 19th and early 20th centuries. The dwellings are characteristically large, with lushly landscaped lots, affording privacy and a sense of seclusion. Typically, lot contours reflect the natural terrain and the winding streets respond to the topography. Bordering the district is Houghton Garden, a unique City-owned public historic garden created by Martha Houghton with assistance of landscape architects Warren Manning and Wayne Stiles.
Chestnut Hill is known for the quality, consistency and architectural significance of its houses particularly those built from the mid- 1850s through the early 20th century. Many of these were architect-designed, and were intended to fit gracefully into the topography, amid the rocky outcroppings and tall trees. Colonial Revival, Georgian Revival, and Shingle styles predominate. The gardens of Chestnut Hill are a special delight. The presence of the nearby beautiful Reservoir and the abundance of retail establishments in the area add to the appeal of Chestnut Hill.