For almost two centuries these grounds have been part of country estates owned by influential and wealthy men. The magnificent specimen trees which they planted here may be ranked as a feature of interest second only to the mansion itself. Approximately two score species and varieties are represented, many of them from Europe and Asia. Trees of foreign origin include European ash, European beech, English elm, Norway spruce, Norway maple, the red-leaved Japanese maple, and a ginkgo, or Chinese maidenhair-tree. This ginkgo is among the largest of that species in the United States. Among the native American trees represented are sugar maple, flowering dogwood, eastern hemlock, Kentucky coffeetree, white oak, black oak, eastern white pine, and blue spruce. Other fine examples of their kind include large beeches, bur oak, and a great cucumber magnolia. Many of these trees are labeled. _Pavilion._ Designed by McKim, Mead, and White, this building was erected by Norcross Brothers in 66 working days, September 8 to November 24, 1895, on the site of the old Langdon carriage house. Cost of the structure probably exceeded $50,000. The pavilion was used by the Vanderbilts during the construction and furnishing of the mansion, and, later, on weekends in the winter season when they came to Hyde Park for winter sports. The pavilion was also used to house the overflow of guests from the mansion. The pavilion represents an adaption of classic Greek architecture. Certain liberties have been taken in the interest of functional arrangement, such as the placement of window openings and modifications necessary for the captain’s walk on the roof. The result is a pleasing combination of classic form and informal detail. [Illustration: _Ginkgo, or Chinese maidenhair-tree._] _Gardener’s Cottage and Tool House._ These two buildings, located south of the mansion, are the only structures on the estate that antedate the Vanderbilt era. Walter Langdon had them built in 1875 according to the design of John H. Sturgis and Charles Brigham, architects of Boston, Mass. Neither building is open to the public. _The Italian Gardens._ These gardens, which lay south of the mansion, may possibly date back as far as Dr. Samuel Bard’s era in 1795. They certainly existed in 1830 as a part of Dr. David Hosack’s estate, and the later owner, Walter Langdon, continued to maintain them. Landscape architect James L. Greenleaf radically revised and enlarged the gardens in 1902-3 for Frederick Vanderbilt.