Marble House is one of the Gilded Age mansions of Newport, Rhode Island, now open to the public as a museum. It was designed by the architect Richard Morris Hunt, and said to be inspired by the Petit Trianon at Versailles (which it resembles in little more than pilasters and balustrades). Grounds were designed by noted landscape architect Ernest W. Bowditch. Marble House was built between 1888 and 1892 for William Kissam Vanderbilt, grandson of Commodore Cornelius Vanderbilt. The house was a social landmark that helped spark the transformation of Newport from a relatively relaxed summer colony of wooden houses to the now legendary resort of opulent stone palaces. It was reported to cost $11 million, of which $7 million was spent on 500,000 cubic feet (14,000 m³) of marble ($260,000,000 in 2009 dollars). Upon its completion, Mr. Vanderbilt gave the house to his wife Alva Erskine Smith as her 39th birthday present. William Vanderbilt's older brother Cornelius Vanderbilt II subsequently built the grandest of Newport cottages, The Breakers, between 1893 and 1895. After the Vanderbilts divorced in 1895, Alva married Oliver Hazard Perry Belmont, moving down the street to Belcourt. After his death, she reopened Marble House and added a Chinese Tea House on its seaside cliffs, where she hosted rallies for women's suffrage. She sold the house to Frederick H. Prince in 1932. Prince's estate gave the house and its furnishings to the Preservation Society of Newport County in 1963. In 1971 it was added to the National Register of Historic Places. Five years later the Department of the Interior designated it, and the Bellevue Avenue Historic District in which it is located, as National Historic Landmarks.