The original Elizabethan house in Clandon Park was replaced by this Palladian Mansion, designed by Giacomo Leoni, in approximately 1730. The park had been purchased in 1641 by Sir Richard Onslow, MP for Surrey. It remained in the Onslow family until 1956 when, experiencing the same problems of maintenance costs seen in last night's episode of Downton Abbey, Lady Iveagh donated it to the National Trust.
The gardens, which were landscaped by Capability Brown, were later added to by a Grotto and a Maori Meeting house.
The Maori Meeting House called Hihemihi was brought from New Zealand by the 4th Earl of Onslow, William Hillier Onslow, when he returned from his duties as Governor of New Zealand.
During World War One, the 5th Earl, Richard Onslow offered the house as a war hospital. His wife, Violet, Countess of Onslow became Commandant of the Military Hospital, from 1915 until 1919.
Update Plans for the future
My memories of The Surrey Infantry Museum at Clandon House http://somerville66.blogspot.co.uk/2015_04_01_archive.html