Bear Island is a remote island in the North that is home to House Mormont. It lies within the Bay of Ice north of Deepwood Motte and south of the Frozen Shore. The Mormonts live at Mormont Keep.
The island contains old gnarled oaks, tall pines, flowering thornbushes, moss-covered grey stones, and steep hills with streams. Aside from a few crofters, the inhabitants of Bear Island live along the coasts and fish the seas.
Current Occupant/Ruler: Lady Lyanna Mormont, Niece of Jeor Mormont, former Commander of the Night’s Watch. Cousin of Jorah Mormont
Dragonstone is a castle located on the island of the same name at the entrance to Blackwater Bay. Located below the Dragonmont and shaped from stone to look like dragons, Dragonstone was the original seat of House Targaryen in Westeros, and had been colonized and fortified as the westernmost outpost of the Valyrian Freehold. The castle has a dark reputation.
After Aegon's Conquest of the Seven Kingdoms, Dragonstone in the newly-created crownlands served as the seat of their heir apparent, known as the Prince of Dragonstone. After Robert Baratheon overthrew the Targaryens in Robert's Rebellion, he gave the castle to his brother Stannis, creating House Baratheon of Dragonstone.
Current Occupant/Ruler: No Current Occupants. Formerly the Targaryens followed by Stannis Bartheon
3. The Eyrie
The Eyrie is an ancient castle and seat of House Arryn, one of the oldest lines of Andal nobility, within the Vale of Arryn. It is situated in the Mountains of the Moon astride the peak known as the Giant's Lance, several thousand feet above the valley below. Although small compared to the seats of other Great Houses in Westeros, the Eyrie is considered impregnable to attack. During winter years, the Arryns seek refuge against the cold at the base of the mountain in the Gates of the Moon.
Current Occupant/Ruler: Robin Arryn, Son of Jon Arryn and Lysa Tully, Nephew of Catelyn Tully.
The castle has five towers of dizzying size, with equally monstrous curtain walls. The walls are incredibly thick and its rooms are built on a scale that would be more comfortable for giants than humans.
Harrenhal covers three times as much ground as Winterfell and its buildings are so much larger that they can scarcely be compared. Its stables can house a thousand horses, its godswood covers twenty acres, and its kitchens are as large as Winterfell's Great Hall.
However, much of Harrenhal has far gone into decay. The Whents use only the lower thirds of two of the five towers, letting the rest go to ruin, and many places in the castle have not been entered in decades. Bats infest the tops of some of the towers.
Upon Harrenhal’s completion, Harren boasted that his new fortress was impregnable. However, he did not account for Aegon the Conqueror and his dragons invading Westeros. On the very day Harren took up residence, Aegon came ashore at what would become King's Landing. The dragons were not obstructed by high walls and forbidding towers and roasted Harren alive in the tallest of the towers, now known as the Kingspyre. Harren and all his line perished in the burning of Harrenhal. Due to the extreme heat of dragonflame, the castle took on a charred, melted appearance.
Current Occupant/Ruler: Petyr Baelish, otherwise known as “Littlefinger” is the current Lord of Harrenhal
5. Horn Hill
Horn Hill is the seat of House Tarly in the Reach. Located on an eponymous hill, the castle lies south of Highgarden and a hundred leagues northeast of Oldtown among the thickly-wooded foothills of the Red Mountains. The Tarlys are marcher lords of the Dornish Marches.
There is a pond that lies below the castle. Given the Tarly huntsman sigil and Lord Randyll Tarly's threats to kill Samwell Tarly while hunting, it may be surmised that the woods around Horn Hill are teeming with game.
Current Occupant/Ruler: Lord Randyll Tarly, Father of Samwell Tarly and Dickon, the Heir of House Tarly.