This island is dominated by a massive fortress that runs nearly to the edge ofthe landmass, surrounded by 20-foot high stone walls manned at all hours by agents of the Xanathar. Atop these walls are cannons that shoot alchemist's fire and ballistas, which keep the island safe from invaders.
The massive subterranean lake in which Skull Island sits is called the Skull Pool, and is the first part of Skullport most people see. The ceiling of the cavern is dome-shaped and 120 feet high at its peak. A massive, hollowed-out column rises from Skull Island all the way to the ceiling.