While most of Beleriand was lost under the Great Sea at the First Age's end, a very few regions survived as islands, and one of these held the Stone of the Hapless near Cabed-en-Aras. It is possible, therefore, that some part of the ravine may have survived as part of Tol Morwen (as the later island was known).

The geography of the region around the Crossings of Teiglin is not well mapped, and the exact location of Cabed-en-Aras is open to conjecture. The location shown on this map is based on a comment in Narn i Chîn Húrin referring to Niënor crossing the bridge of Celebros in Brethil. From there, we're told, there was a view of the Ravines of Teiglin some two miles to the west, and this view set Niënor shuddering.

Niënor's shuddering was apparently a foresight of her later death at Cabed-en-Aras, implying that that was what she saw two miles to the west. This isn't absolutely certain (Niënor might have been reacting simply to seeing the Ravines in general, rather a specific place) but lacking more precise detail we use these comments from the Narn as a guide to the geography of this area.