Inside the most expensive zip code in Silicon Valley, where tech moguls like Eric Schmidt and Paul Allen have their mansions

From the looks of it, Atherton could be any ritzy suburb in America.

But it isn't anywhere. Atherton is an idyllic town located on the San Francisco Peninsula, where even modest homes go for millions of dollars. It is the third priciest zip code in the US and the most expensive in Silicon Valley, according to Forbes.

It's no surprise that tech billionaires - including Microsoft cofounder Paul Allen, HP CEO Meg Whitman, and Google chairman Eric Schmidt - come home to Atherton's 94027. The town's prestige, privacy, and proximity to major tech companies draw ultra-rich homebuyers, who often pay all cash and bid hundreds of thousands of dollars above asking price.

Here's what it's like inside Atherton.