where are the library files?

HI,
I use Arduino IDE 1.6.7 for Mac.
Usually I find the library files are in /User/Document/... That is when I install it manually. But When I install by using Add .ZIP Library. I can't find it in that directory. Where does it go? And how do I remove it?

Libraries installed using Add .ZIP Library are located in the libraries folder under your sketchbook folder. To find the location of your sketchbook see File > Preferences > Sketchbook location.