Stronghold Skulls are one of the 5 variants of skulls in Sea of Thieves. Stronghold skulls are the most valuable Trophy Skull in the game.
Stronghold Skulls are typically obtained through defeating Skeleton Captains during Fortress Raids, by using their key to unlock the vault. There is also a chance for these to drop when defeating a Megalodon.
How to Identify
Stronghold Skulls are identifiable by its bright, flame-like glow (The brightest of the skulls), gold teeth, and gleaming green gemstones set in its sockets. A large crack in the top reveals more green gems within, and is held in place by leather straps wrapped around the skull.