Westeros is one of the three known continents in the world. Most of its area is covered by the Seven Kingdoms.The continent is long and relatively narrow, extending from Dorne in the south to the Lands of Always Winter in the far north, and was originally divided into seperate independant kingdoms but after the War Of Conquest all the regions south of the Wall were united under the rule of House Targaryen into a nation that is known as the Seven Kingdoms.

(Source: lecrawleys)