Imagine a single building that spans the width of San Francisco, a distance of approximately seven miles (2 leagues). For anyone familiar with the city, imagine a stone fortress stretching from the Cliff House in the west, to the Embarcadero in the east, which gives a rough approximation of Casterly Rock’s colossal base. The largest castle in the Seven Kingdoms, Casterly Rock is almost a city unto itself, complete with its own docks and shipyards distinct from those of Lannisport.
The Lannister’s ancestral fortress must be considered vertically as well as horizontally, for Casterly Rock digs deep into the bowels of the earth, even as it reaches high into the sky. If it existed in the real world, Casterly Rock would be taller than almost every skyscraper mankind has ever built. According to The World of Ice and Fire, the Casterlys built a ringfort at the Rock’s peak to survey their kingdom; their surveys must have proven as short-sighted as Tywin Lannister’s preparations for the coming winter, as the summit of Casterly Rock is literally in the clouds.
Under the cut, I attempt a comprehensive analysis of Casterly Rock, along with some wild speculation. Well-reasoned counterarguments and discussion are most welcome. Please feel free to point out any inaccuracies so that I may edit and correct them.