Looking for a cave near Harviken (SPOILERS)

[JMO]

OK so I am post story-line, now in NG+ just checking things out. So this post is just out of sheer curiousity.

I was on that island in the South of Skellige with Harviken and Trottheim. My Witcher Senses are telling me there is something underground but I cannot find the entrance.

If you make a beeline from Harviken to the Place of Power, there is a hill you climb. When I get to this point on the map[imgur.com] then my senses tell me that directly beneath me there is some sort of creature making a snarling sound. But I cannot figure out how to find this creature.

I tried going all around the hill looking for some sort of cave entrance but could not find one. Yet my senses tell me that this thing is underground directly beneath this point.

I've already hit the cave on the coast, immediately to the south of me on this map and cleared it out. It was one big room with some Endregas. I went all around there looking for some passage off but didn't find one.

So does anyone know where I should look?

[d2Nub]

https://steamcommunity.com/sharedfiles/filedetails/?id=933745011
https://steamuserimages-a.akamaihd.net/ugc/769399818063441046/7011F08790DB2DF64540A485B122A72E98E26632/

[JMO]

Thank you! I must have gone right past that cave opening a dozen times and never saw it or was notified about it by the game.