Dragonstone currently the seat of House Baratheon, formerly the seat of the Prince of Dragonstone, crowned prince of House Targaryen
Dragonstone is the name of the island located at the entrance to Blackwater Bay and the castle thereon, which was shaped from stone to look like dragons. Dragonstone was the original seat of House Targaryen in Westeros during the Valyrian Freehold, later, after the conquest of the Seven Kingdoms, the island served as the seat of the heir apparent, known as “The Prince of Dragonstone”. After Robert Baratheon overthrew the Targaryens, he gave the island to his brother Stannis, creating House Baratheon of Dragonstone.
Dragonstone is a volcanic island at the mouth of Blackwater Bay, created by the active volcano, Dragonmont. The castle of Dragonstone is a small fortress located on the face of the volcano and has a dark reputation. Outside its walls sits a small fishing village on the stormy coast. Beneath the mountain Dragonmont are rich deposits of dragonglass.
The ancient fortress of Dragonstone was built using advanced Valyrian techniques of masonry that were lost in the Doom, causing it to look unique among all the castles in Westeros. The citadel of Dragonstone is wrought all of black stone, its towers carved into the shapes of dragons, and 1,000 gargoyles carved into various shapes serve as brooding crenellations along the three curtain walls (x).
Dragonstone by Ted Nasmith