As early as 1909, Pierre S. du Pont was hosting garden parties at his recently-acquired weekend home, Longwood, in the Brandywine Valley of southeastern Pennsylvania. By 1914, he had created an amphitheater southwest of the manor for the performance of concerts and plays. The design of the Open Air Theater was a larger version of one found at Villa Gori, near Siena, Italy. It included dressing rooms beneath a two-tiered stage backed by a grassy hill and framed by columnar arborvitae, and a lawn auditorium with a 1,500-seat capacity. Du Pont originally installed hidden fountain jets in the stage floor for theatrical effects; in 1927 the fountain system was greatly embellished during a renovation. Under the removable flooring of the proscenium, he added seven circular basins and jets that form a ten-foot water curtain; on the upper level, he installed two central basins and roof fountains in the wings. The mechanics are hidden under the stage, and over 600 colored lights illuminate the fountains. The enclosed amphitheater is secluded by Kentucky coffeetrees, saucer magnolias, bald cypresses, and Canadian hemlocks. Its seasonal garden is planted in muted shades and features yuccas, prickly pears, and ornamental grasses. Red brick aisles set into the lawn, decorative masonry urns, and two sets of stone stairs add architectural variety.