interior design of the mansion. The initial eclectic structure took six years to complete. Before being occupied, it was substantially rebuilt into its present four-story Classical Revival Georgian form. Completed in 1913, it has two basement levels filled with interconnecting passageways and service tunnels. The home's interiors were designed by Ogden Codman Jr., and feature collections of Chinese and European ceramics, fine furnishings, and 20th-century art. The estate was designated a National Historic Landmark in 1976. In 1979, its occupant, Nelson Rockefeller, bequeathed upon his death his one-third interest in the estate to the National Trust for Historic Preservation. Today, Kykuit is open to the public for tours conducted by Historic Hudson Valley. Kykuit was renovated and modernized in 1995 by New Haven architect Herbert S. Newman and Partners. Included were major infrastructure changes enabling the estate to accommodate group tours of the first floor and art gallery, as well as a reconfiguration of third and fourth floor staff quarters into guest suites. Gardens Initially, landscaping of the grounds was given to the firm of Frederick Law Olmsted, who had designed Manhattan's Central Park. Rockefeller Senior was unhappy with this work however and assumed control of the design himself, transplanting whole mature trees, designing lookouts and the several scenic winding roads. In 1906, the further design of Kykuit's grounds was undertaken by the architect William Welles Bosworth, who designed the surrounding terraces and gardens with fountains, pavilions and classical sculpture. These gardens in the Beaux-Arts style are considered some of Bosworth's best work in the United States, looking out over very fine views of the Hudson River. A few years later, Bosworth would design the Neo-Classical main building complex and landscaping for the new campus of the Massachusetts Institute of Technology in Cambridge, Massachusetts. Bosworth's original gardens still exist, with plantings carefully replaced over time, although his entrance forecourt was extended in 1913. The terraced gardens include a Morning Garden, Grand Staircase, Japanese Garden, Italian Garden, Japanese-style brook, Japanese Tea-house, large Oceanus fountain, Temple of Aphrodite, loggia, and semicircular rose garden. Art collection Distributed through the estate are numerous artworks reflecting the tastes of the past occupants. Governor Nelson Rockefeller collected and displayed many 20th century artworks, with a focus on abstract works from the 1950s through the 1970s. He was also very influential in the selection of artworks for the Governor Nelson A. Rockefeller Empire State Plaza Art Collection,