Was it actually "the costliest monument a man has ever built to himself"? The astonishing, ostentatious inspiration for the fictional Xanadu estate of "Citizen Kane," William Randolph Hearst's San Simeon was a private kingdom constructed in 1919, home to the media mogul and one of the largest residences ever built. This episode of "America's Castles" takes you inside the legendary mansion, even affording glimpses of areas kept off-limits to the public. 50 min. Standard; Soundtrack: English Dolby Digital stereo.