Use Google Maps to make a Tree Structure as in Khanacademy.org

I was just surfing out the site Khanacademy.org, and just seeing their practice session, when i came across this page, Here I saw something odd, they use google maps to create the structure shown below:

enter image description here

Now I am wondering that how can they make use of Google Maps to create a course structure tree like this?

PS - If you can't see the link to this page directly, then I think you need to register.

What is Place_id?

A place ID is a textual identifier that uniquely identifies a place. The length of the identifier may vary (there is no maximum length for Place IDs).

How do I get lat long from Google places API?

You could use place. geometry. location. lat() and place.

Here's how they did it