It is located in the north of The Reach, bordering the former lands of House Osgrey.
It's outer walls stand thirty feet high and have crenelations at the top. It has towers at each corner. It is surrounded by a moat. The castle has the capacity to hold twenty times as many smallfolk as Standfast.
The castle of Coldmoat was first raised by lord Perwyn Osgrey when the lands of the Reach were still ruled by House Gardener. The castle was taken from the Osgreys by King Maegor after Lord Ormond Osgrey opposed Maegor's laws.
The castle is visited by the future King Aegon V Targaryen when he journeys with Ser Duncan the Tall. At that point the castle is held by Lady Rohanne Webber. The lands pass into the possession of House Osgrey once again when Ser Eustace Osgrey marries Lady Rohanne.