New Apple Photos app - location of photos on disk

We can barely call it new, but in a way it is, at least newer than the dreaded iPhoto (that I'm pretty sure will slowly die), Apple's Photos app is definitely one application worth having a look if you are using one of Apple's computers (like I do). I actually stopped working iPhoto and went over to Google's Picasa, but since Photos is around, I learned to like it; so far no real complaints. However, you might be the kind of guy who doesn't just like to see those images inside the app, but time to time you may want to just be sure you have it somewhere on the disk, and be able to manipulate it, copying or whatnot. Well, I have good news to you: those images you imported into the Photos app can be retrieved on the disk, and here is their location (of course, replace your_username with yours):