Atherton, California, a favorite residential enclave of business moguls and tech titans—it’s one of the wealthiest ZIP codes in the country—is prized for its expansive estates tucked into a peaceful, wooded setting within easy commuting distance to San Francisco and other Silicon Valley tech industry centers.
Last year, venture capitalist Marc Andreessen put a $33 million price tag on his longtime home in the 94027 (it sold earlier this year at $27 million), and…

