Coldmoat has crenellated outer walls standing thirty feet high with towers at each of the corners. It is surrounded by a moat. The lion of House Osgrey is carved in checkered squares in the stone above Coldmoat's gates, although it has been worn down by the elements.
Within Coldmoat's yard are kennels, stables, a smithy, and a seven-sided wooden sept with windows of leaded glass. The audience chamber of the Webber is decorated with tapestries of battles and tourneys, and the stone floors are covered with rushes. Coldmoat also contains a maester's tower.
The castle can support twenty times as many smallfolk as Standfast. The landscape near Coldmoat contains fields of barley, wheat, and corn, as well as six orchards of apples, apricots, and pears. The Webbers are proud of their horse breeding as well.
Once the greatest of the four castles of House Osgrey, Coldmoat was raised by Lord Perwyn the Proud. However, the castle was taken from the family during the reign of Maegor I Targaryen because Lord Ormond Osgrey opposed King Maegor's laws. At some point, House Webber became the Lords of Coldmoat.
Addam Osgrey served at Coldmoat as a page and a squire. His father, Ser Eustace Osgrey of Standfast, once visited Coldmoat to suggest a marriage between Addam and Rohanne Webber, the daughter of Wyman Webber, but the Lord of Coldmoat refused Eustace. In return for House Osgrey's support in the First Blackfyre Rebellion, Daemon I Blackfyre promised to give Coldmoat to Eustace. Addam and Daemon were slain in the Battle of the Redgrass Field, however.
When Rohanne was Lady of Coldmoat, an Osgrey man named Dake stole sheep from Webber land. When Eustace did nothing in response to her complaints, Rohanne's knights abducted Dake and sunk him in the castle's moat. Rohanne's men later dammed the Chequy Water and diverted the stream to fill her castle's moat, angering Eustace.
Ser Duncan the Tall and his squire, Prince Aegon Targaryen, visited Coldmoat as Eustace's envoys, but Rohanne revealed a royal decree granting the Webbers rights to the Chequy Water. After Duncan defeated Ser Lucas Inchfield in a trial by battle, Rohanne agreed to wed Eustace, thereby bringing Coldmoat under the joint control of House Webber and House Osgrey.
—thoughts of Duncan the Tall