Stoneleigh: A Natural Garden, Botanical garden in Villanova, Pennsylvania, US

Stoneleigh: A Natural Garden is a 52-acre property in Villanova, Pennsylvania, owned by the conservation non-profit Natural Lands. Its Tudor Revival mansion, designed in part by Olmsted Brothers, houses the Organ Historical Society and hosts programs. Trees, pathways and gardens laid out by notable landscape architects over the past century surround the house.

Edmund Smith, a Pennsylvania Railroad executive, bought 65 acres in Villanova in 1877 and built a residence. In 1900 Samuel Bodine, head of United Gas Improvement Company, acquired the property; after his death in 1932 it was subdivided and sold. Otto Haas, co-founder of Rohm and Haas, bought the southwestern portion, and his son John and wife Chara acquired it in 1964, keeping it for five decades.

The name Stoneleigh comes from the Haas family estate, and the Tudor Revival mansion now houses the Organ Historical Society, an international non-profit devoted to pipe organ history. Visitors can attend programs in the mansion and see gardens shaped by Olmsted Brothers, sons of Frederick Law Olmsted, over the past century.

Natural Lands maintains the garden and offers free access with walking paths, educational displays, and seating areas throughout the grounds. The trails are well marked, making it easy for visitors to explore at their own pace.

The property successfully defended against an eminent domain claim through legislation protecting conservation easements in Pennsylvania. This legal battle shaped its survival as a natural space in a growing area.