Bourn made his fortune from the Empire Gold Mine in Grass Valley and the Spring Valley Water Company, which supplied San Francisco's water. He commissioned architect Willis Polk to design Filoli in 1915, and the house was completed in 1917. The gardens, designed by Bruce Porter and later expanded by Isabella Worn, feature a sunken garden, a walled garden, a rose garden, and a woodland garden that peaks in spring with explosions of color. The estate sits at the head of Crystal Springs Reservoir, a coincidence that pleased Bourn -- the water magnate living above his own product.

After Bourn's death, the estate was purchased by William P. Roth and his wife Lurline Matson Roth of the Matson Navigation Company fortune. The Roths maintained and expanded the gardens for over four decades. In 1975, Mrs. Roth donated the house and gardens to the National Trust for Historic Preservation. Filoli opened to the public in 1977 and quickly became one of the most visited historic homes in California. Television viewers may recognize it: the exterior served as the Carrington mansion in the opening credits of Dynasty.

The formal gardens are Filoli's greatest achievement. Organized into a series of garden rooms separated by walls, hedges, and allees, they create an experience of sequential discovery -- each space opening onto the next with its own color palette, plantings, and character. The walled garden is structured around geometric beds; the woodland garden is wild and naturalistic. In spring, the estate's hillsides are carpeted in wildflowers. The gardens exist at the scale of ambition that only sustained wealth and sustained care can maintain, tended now by staff and volunteers who understand that a garden is never finished.