Westeros is one of the three continents in the world. On the east of Westeros, across the narrow sea, lies the huge continent of Essos. Further south east lies the continent of Sothoros, which is mainly unexplored. To the south lies the Summer sea in which lies the Summer islands. Th capital city of Westeros is King's Landing.
Westeros is a long, narrow continent which extends for about 9000 miles north to south and 900 miles east to west. In the southernmost tip of Westeros lies the Kingdom of Dorne, ruled by the House Martell and to the extreme north, beyond The Wall lies the Land of Always Winter. This region is mostly uncharted due to extremely cold temperatures. The region is inhabited by wildlings, supposed descendants of the first men. The supernatural creatures known as The Others are also believed to dwell here. This region is seperated from the rest of the continent by The Wall. The Wall itself is supposed to be hundred leagues in length.
Most of Westeros is occupied by the Seven Kingdoms. Directly south of the wall lies the region known simply as "The North". The North is the largest of the seven kingdoms although sparsely populated. This region is ruled by the House Stark from their seat at Winterfell. The weather here is usually cold and snowy. The iron islands lie to the west. It is ruled by the House Grejoy and the inhabitants are called the Ironborn. They are a formidable naval power. Next lies the fertile area between the trident known as Riverlands. It is ruled by the House Tully. To the west of Riverlands lie the Westerlands, a small region but rich in gold and silver mines. This region is ruled by the very powerful House Lannister from their seat at Castrely Rock. To the east of the Riverlands lies the Vale of Arryn. This region is encompassed by the Mountains of the Moon. This region is ruled by House Arryn from castle Eyrie. Next is The Crownlands,ruled directly by the iron throne and includes the capital city of King's Landing. South of Westerlands lie the Reach, a large land ruled by House Tyrell of Highgarden. The Stormalands are ruled by the Bratheons. To the extreme south lies the kingdom of Dorne. It is ruled by House Martell.
Westeros' climate shifts from cold winter in the north to arid in the south. In Westeros the seasons last for couple of years.
Westeros' first dominant civilization was the Children of the Forest who reigned supreme and unchallenged, living in harmony with nature and worshiping the Old Gods of the Forest and great masters of powers long thought as gone, until the arrival of the First Men from Essos who crossed the Arm of Dorne, who were received with hospitality, expanding their domain until their cutting down of the sacred weirwood trees began a war for supremacy amongst both races, in which the First Men dominated in strength due to wielding arms of bronze and great numbers against the Children's beasts and magic, which ended in the Arm being broken