the ancient key is an item found on the island the player starts on.
not much is currently know about the key.
it can be found under a rock in the teak forest on a small island nexus too a small island with a tough screw on it.
Where too find
the rock can only be accessed at night time and will disapear after you leave the area once it becomes day.sleeping on the island does not cause the player to become stuck until night
the ancient key has a small chance of appearing after the player punches the rock.
the ancient key can be used like most tools which could mean that there is some kind of chest it can open