Hallock the Invincible
Hallock, the seat of the royal family of Sobrin, may well be the site of more sieges than any other place in the entire bay, including the regularly-invaded Green Tower of the elves. A high-walled fortress atop a large, sheer-faced hill, it has undergone numerous fortification projects since its construction centuries before. The fortress itself is far from the largest in the kingdom, but its high vantage point, combined with the surrounding forests and the fact that the inhabitants have turned the plains nearby into marshlands, afford the castle virtual invulnerability to siege weapons simply because there is nowhere nearby to set them down for firing.
Once, there was a wide path leading up to the gates. Centuries of magically-assisted weathering and reshaping have rendered the wide causeway down into a series of narrow switchbacks, guarded by thick gates and in clear view of the archers on the castle walls. The sides of the hill rise six feet above the path on either side- this, combined with the even, downward slope, allows boiling oil from the top of the hill to flow all the way down to the bottom without any spillage. Powerful wards set into the gatehouses are primed to discharge energy on anyone who walks through them when activated, though they are usually left deactivated so as to permit travel to and from the castle.
While it does not have the massive underground storehouses common to later castles, Hallock is extremely difficult to cut off – it has a direct route to the sea, and water-facing trebuchets are a deadly threat to ships at a great enough distance that an entire armada would be required to successfully blockade it, and even then, the royal family has long kept secret the series of portals out to other holds, and even to the islands of Chara, that lurk within the hill.
It should be noted, however, that Hallock’s reputation for invulnerability only really holds true in the event of a direct assault; a number of kings and nobles have been assassinated within its walls, and the sea caves at the back provide easy enough access for the truly determined spy or saboteur.