The 1,000-acre Country Place Era home of Henry Francis du Pont, now the site of the Winterthur Museum and Gardens, is set into the rolling landscape of the Delaware Valley. The extensive collection of native flora and a rich diversity of exotic vegetation collected from around the world manifests du Pont’s expertise as a horticulturist. The gardens also reflect the more than 50 years of friendship and professional collaboration with Marian Coffin, whom du Pont met in 1901. The early designs reflect the prevailing Italianate prototype of Charles Platt. Coffin oversaw a series of design revisions in the terraces around the changing architecture. Her office also chronicled and managed the ongoing horticultural expansion, inspired by the writings of both William Robinson and Gertrude Jekyll. Extending from the swimming pool into the surrounding woodland are acres of naturalistic gardens laced by winding paths, revealing streams, ponds, and magnificent native trees. Open meadows enrich the diversity of the landscape, both visually and environmentally, and suggest the working farm of the former estate. Winterthur was listed on the National Register of Historic Places in 1971.