Built late 19th-early 20th c.
Town of Islip, Suffolk County

Situated along the Connetquot River in the western portion of Oakdale, Idle Hour is the former 900-acre estate of railroad mogul and financier William Kissam Vanderbilt I. Many of the estate’s exceptional buildings were designed for Vanderbilt by celebrated American architectural firms like Hunt & Hunt and Warren & Wetmore. Vanderbilt was drawn to the area by the nearby Southside Sportsmen’s Club (now Connetquot River State Park Preserve) and joined other wealthy Club members who commissioned lavish country retreats on the Great South Bay. These estates historically link the late 19th century development of Long Island’s South Shore to the prosperity generated by America’s commercial and industrial growth during the period. Following Vanderbilt’s death in 1920, the estate was subdivided, but the buildings remained and a lively suburban community grew up around them in western Oakdale. Today, Idle Hour’s exceptional historic buildings continue to embody the surrounding community’s strong ties to the Vanderbilt-era, a connection that is widely recognized and celebrated by those who live and work in Oakdale.

Unfortunately, the Town of Islip has yet to officially recognize these buildings as local landmarks, leaving many of Idle Hour’s most important structures, including the mansion, vulnerable to demolition. The structures now most at risk were once a part of the former Dowling College campus. After Dowling College closed in 2017, its Idle Hour properties were sold at auction to NCF Capital Ltd., a Hong Kong-based company with ties to China UCF Group Co., a Beijing conglomerate. According to Newsday, the sale closed in August 2017 and the endangered Idle Hour properties are now owned by Mercury International LLC of Delaware, an affiliate of NCF Capital Ltd.

Future plans for the Idle Hour structures are unknown, but without landmark protection, all of the structures are threatened by demolition and redevelopment. The buildings and grounds have stood largely unoccupied for several months​ and are beginning to show signs of deterioration.

Preservation Long Island advocates for the Town of Islip’s Board to designate Dowling College’s former Idle Hour properties as local landmarks in order to protect and preserve these significant historic resources in the heart of the Oakdale community from demolition or extensive redevelopment.


Town of Islip residents should communicate their support for designating Idle Hour a local landmark and adding it to the Town’s Planned Landmark Preservation Overlay District by contacting:

Islip Town Board
Town Hall, 655 Main St, Islip, New York 11751
Email: townclerk@islipny.gov
Individual contact information for the Islip Town Supervisor and Board Members is available here.

Planning Board, Town of Islip
Town Hall, 655 Main St, Islip, New York 11751
Phone: (631) 224-5450; Fax (631) 224-5444
Email: commissioner-pd@islipny.gov