From San Francisco's street art to the eight months of flowing fog, it all starts to make sense when you let your curiosity out for a stroll with Thinkwalks.

* Why was the city put here to begin with?
* Where can I see an earthquake?
* Why was the Golden Gate Bridge built like that?

Rather than, "Where do I shop or eat?", this guide answers the more subtle, "How did the city come to be the way it is?"

Whether you're bursting with vacationer's enthusiasm or have lived in an Ess Eff Victorian since the naked mammoths roamed, this app opens your eyes to how it all fits together.

And when you graduate from Everything Explained, you'll be pleased to dig deeper with the next Thinkwalks guide to San Francisco, Local Nerd!

Everything Explained is part of the Know What network, a collection of apps from brilliant, informed people – each with dozens of favorite places and best local secrets. So you can always Know What, no matter where you are.