Hi,

I remember i met someone at the top of a mountain near the place you are looking at.

I was swimming from Shattered Coast, and i found a path to climb.
But i did'nt see any castle, just a man with a fireplace and fish.

Thats another island next to the mysterious isle. I've been there too :)

I will search again then :)

on one of those finger looking island parts i once encountered some sort of bug boss that spawned little bugs, it killed me and after that i went back multiple times but never found it again. spooky.

I know him. He can spawn everywhere in the map. (I killed him :D)

I too have swam all over this place looking for a tunnel or door or ramp. Still a mystery. I know you can climb a hill on the north side of this island, but it doesn't even come close to getting you high enough to access the top.

On the north east corner of the island you will find a way to get out of the water. There are some trees and a kind of wall. With the mage teleport and some luck you can port on top of the wall and then run to the castle.

Not sure about the wall, but I am familiar with the place with the trees on the NE side. I've tried a number of times, but have been unable to get up. Trying to Flick up a hill also ends up killing me, so I don't even like to do that.

I don't think its intended for us to get up that way, so I'm assuming there is either another way, or there will be in the future.

Have you been there Tril?