As promised here it is, we talk about the wall that separates the land of always winter from the realms of men and about Bran/Brandon the Builder.

I'll briefly touch upon the Long Night since that is a video on itself that still needs to be done.

The video includes some spoilers from season 6, so please be aware. Also if the theory is correct then it contains spoilers for season 7 as well.

The video contains history, description, and the best theory in my mind about the function and the importance of the wall, since it is EXTREMELY IMPORTANT.