World's End (location) fabled end of the world, lying far to the west of the Island of Cos . Those with Second Knowledge  know this to be but a salior's tale, and that Gor, like Earth, is round

We did not know where lay the world’s end, but we knew where It must be sought. The world’s end was said to lie be­yond Cos and Tyros, at the end of Thassa, at the world’s edge. No man had sailed to the world’s end and re­turned. It was not known what had oc­curred there. Some said that Thassa was end­less, and there was no world’s end, only the green wa­ters ex­tend­ing for­ever, gleam­ing, beck­on­ing the mariner and hero on­ward, on­ward until men, one by one, had per­ished and the lonely ships, their steer­ing oars lashed in place, pur­sued the voy­age in si­lence, until the tim­bers rot­ted and one day, per­haps cen­turies later, the brave wood, warm in the sun, sank be­neath the sea.
“The ship is ready,” said Samos, look­ing at me.
Oth­ers said, in sto­ries rem­i­nis­cent of Earth, and which had doubt­less there had their ori­gin, that the world’s end was pro­tected by clash­ing rocks and mon­sters, and by moun­tains that could pull the nails from ships. Oth­ers said, sim­i­larly, that the end of the world was sheer, and that a ship might there plunge over the edge, to fall tum­bling for days through empti­ness until fierce winds broke it apart and the wreck­age was lifted up to the bot­tom of the sea. In the mael­stroms south and west of Tyros shat­tered plank­ing was some­times found. It was said that some of this was from ships which had sought the world’s end
Book 12, Beast of Gor pp. 27-28