§ Of the Noldor in Beleriand The Silmarillion

Then Ulmo returned to the sea, and Turgon sent forth all his people, even to a third part of the Noldor of Fingolfin's following, and a yet greater host of the Sindar; and they passed away, company by company, secretly, under the shadows of Ered Wethrin, and they came unseen to Gondolin, and none knew whither they had gone. And last of all Turgon arose, and went with his household silently through the hills, and passed the gates in the mountains, and they were shut behind him.