San Francisco is a wealthy tech haven today - but not long ago it was an apocalyptic madhouse

When you think about San Francisco, you probably envision tech companies filled with optimistic twenty-somethings and restaurants with fancy food. Maybe Alcatraz or the Golden Gate Bridge.

But from the late 1960s through the 1970s, the city by the bay was a very different place.

Drugs. Murder. Corruption. Outcasts. That's what San Francisco looked like in the popular imagination - and that stereotype had a lot of basis in truth.

Journalist David Talbot captured the details of this critical time in an amazing 2012 book, "Season of the Witch." While I had a vague sense of some of the city's recent history, many of the details will astound you.

Here's what San Francisco was really like a generation ago...