§ Of the Sun and Moon and the Hiding of Valinor The Silmarillion

And in that time also, which songs call Nurtalë Valinóreva, the Hiding of Valinor, the Enchanted Isles were set, and ail the seas about them were filled with shadows and bewilderment. And these isles were strung as a net in the Shadowy Seas from the north to the south, before Tol Eressëa, the Lonely Isle, is reached by one sailing west. Hardly might any vessel pass between them, for in the dangerous sounds the waves sighed for ever upon dark rocks shrouded in mist. And in the twilight a great weariness came upon mariners and a loathing of the sea; but all that ever set foot upon the islands were there entrapped, and slept until the Change of the World. Thus it was that as Mandos foretold to them in Araman the Blessed Realm was shut against the Noldor; and of the many messengers that in after days sailed into the West none came ever to Valinor - save one only: the mightiest mariner of song.