Isla Crusade,
Flat lying island with long beaches and sand bars
in the middle of the jungle is a small forest with a waterfall in the middle, BUT in the waterfall is a small cave entrance that allows you to venture underground into a treasure room (similiar to barbossas grotto) and guarding this vast treasure is a EITC assasin ghost!!!!
(story of the ghost) He searched all of his life searching for the great treasure of isla crusade, even after loosing most of his crew and his sanity he never stopped searching, it wasnt until after a mutiny that his crew finally left him on what seemed to be a baren wasteland but upon further searching he located what he has spent years looking for, the treasure of the crusades!!!, but he had no way of leaving the island with his gold, so he finally died unable to leave his precious treasure behind he now guards the cavern for any thieves looking to steal it)