In the same year, the Hearst family gave the castle and many of its contents to the State of California. It has since operated as the Hearst San Simeon State Historical Monument and attracts about 750,000 visitors annually.

Who owns San Simeon now?

It's now owned and operated by the California State Park system. Jim Allen, a former Hearst tour guide who's worked at the castle for 30 years, took CNN Travel on a special tour of the property, sharing some secrets of the sprawling complex that a billionaire once called home.

Are there still animals at San Simeon?

On the winding road up to Hearst Castle, you can still spot a variety of animals including Barbary sheep, white fallow deer and Rocky Mountain elk.