Constructed on the largest island just east and south of the Cape of Heroes, the Isle of Deeds, Serpent's Hold is the training grounds for nearly all of the realm's fighting population. Serpent's Hold is a single, compound structure, with an internal castle to house the Lord, Captains, and instructors, meetings halls, and mess hall.
Outside of that, but within the keep's walls, are the barracks, the smithy, the stables, and the training grounds.
Serpent's Hold is less a city than it is a stronghold. Although the keep has been there for some time, very few buildings have sprung up around it. The land is not particularly favorable for farming or hunting, so no one has come to the keep seeking protection. In addition, most of the soldiers move on once they've completed their training, so the only non-warriors who have taken up residence in the area are those who can provide for the Hold's needs, such as blacksmiths, tanners, etc.