Longshore Skull (achievement)

Longshore Skull is a Halo 3 Achievement gained by finding a hidden skull on the map. It is worth 25 Gamerpoints.

Skull
The skull is located behind the air ducts left of the garage door that says "do not block", in the left upper corner of the map (when facing away from the fish taco shop). To grab it, enter monitor mode and fly behind the air ducts, then go back to normal mode and pick up the skull. 

Internal

 * Halo 3 Achievements

External

 * Tutorial Video on Getting All Mythic Skulls