Filoli.  Woodside, California, US.

 

"Mr. and Mrs. William Bowers Bourn had, for many years, anticipated building an estate in the country where they could finally enjoy their retirement; but the War, travels, business, and family obligations had kept them from realizing their dream. Then, in 1915, after years of collecting ideas, they were ready to apply their vision towards planning a project that, in Mr. Bourn's own words, “might be interesting a few hundred years from now. 

Filoli had the distinction of being one of the last country places built on the San Francisco Peninsula and the one that survived the longest in its original design."  Source: filoli.org