It says for over 8000 years because the castle of Winterfell is believed to be built 8000 years ago or more.
Lager (German: storage) is a type of beer that is fermented and conditioned at low temperatures. Pilsner pale lager is the most widely-consumed and commercially available style of beer in the world. Bock, Dortmunder Export and Märzen are all styles of lager. There are also dark lagers, such as Dunkel and Schwarzbier.