Stonedoor is one of the nineteen castles raised by the Night's Watch along the Wall, lying between Greyguard and Hoarfrost Hill in the western reaches of the ice. It stands abandoned, one more empty gate in a Wall the Watch can no longer fully man.
The Long Retreat
In the years of the Watch's strength thousands of black brothers held the Wall from sea to mountains, but as the realm forgot its foes the order withered. Castle after castle was shuttered, and Stonedoor among them; its gate was sealed and its garrison marched away, leaving only wind to walk its battlements.