Quote by Jared:
This is the place I missed....
A missable "named" location for this achievement is in the Southern Shelf - Bay area. The area is called Ebonfloe. This area wasn't required for me to get the Arctic Explorer achievement, so this place was the one I was missing.
To get there:
Southern Shelf
-Fast travel to the southern shelf.
-Leave town down through the path that has a gate.
-Once at the bottom of the hill, go left. (On the map, the place you want to go is on the very southern edge [It's a place called Gateway Harbor] - Go through to the next area)
Southern Shelf- Bay
-Once in the next area, leave the cave and follow the right side of the area (If looking at the map, go left)
-Just keep hugging the edge of the map until you reach an old abandoned ship half reclaimed by the sea
-Head up the little ice hill there and jump across.
-Head through the arch and BAM. You found Ebonfloe.