Winterfell is the ancestral castle and seat of power of House Stark and is considered to be the capital of the North. It is located in the center of the northern province of the Seven Kingdoms, on the Kingsroad that runs from King's Landing to the Wall.
Winterfell is a huge castle complex spanning several acres, consisting of two massive walls and a village located just outside called the "winter town". Winterfell itself has been built around an ancient godswood and over natural hot springs.
The water is piped through walls and chambers to heat them, making Winterfell more comfortable than other castles during the harsh northern winter.
Inside the walls, the complex is composed of dozens of courtyards and small open spaces. Weapons training and practice take place in those yards. The inner ward is a second, much older open space in the castle where archery practice takes place. It is located next to the broken tower. Inside Winterfell stands the Inner Castle, which contains the Great Keep and the Great Hall.