There are only two trips necessary to this remote isle in the game. The first is out of your control, it happens at a certain point in the game. The second time, it becomes the last place you travel to in the game. For the Guardian is here and this is where you eventually face him in your Grand Finale.

The first time you are here though you might pick up a new magic implement, though its not much use against the denizens of the isle.

Terfin
{
  surrounding isle
  {
    (3) vulture
    [77°33’n,37°13’e] reag:pearl
    [80°50’n,29°39’e] reag:pearl
    [85°14’n,31°24’e] potn:serpentwyne
    [86°20’n,26°58’e] brown dragon
    [89°44’s,28°25’e] brown dragon
    [88°4’s,25°27’e] wep+:pole:Crook of Charming
    [85°42’s,25°54’e] brown dragon
    [88°22’s,29°41’e] Dungeon Entrance (covered by a rockfall until Raven mentions it)
    {
      scrl:nnn I've encountered this...
      barrier (drops in the presence of all 8 sigils)
      teleporter (to turfin dungeons)
    }
  }
  front rooms
  {
    kitchen
    {
      (3) drnk:wine bottle
      food:pie
      food:bread
    }
    torture room
    {
      food:cheese
      food:tomato
      drnk:bottle of whiskey
      chest
      {
        (13) coin
        (19) coin
      }
      drnk:wine bottle
    }
    barracks
    {
      (4) bed
      wrymguard
      book:nnn water breathing
      wardrobe
      {
        tool:clean bandages
        weap:1H:scimitar
      }
    }
    anterooms
    {
      gargoyle
      (2) book:nnn book of family
      book:nnn book of ritual
      (2) weap:2H:battle axe
      chest
      {
        potn:purple
        potn:yellow
      }
      potn:black
      potn:yellow
    }
    [59°36’N,104°53’W] dungeon exit
  }
}