J.R.R. Tolkien> The Silmarillion

Taniquetil was the tallest peak of the Pelóri mountains, raised as a defense against the intrusions of Melkor. Taniquetil is considered to be the tallest mountain in the world. The Vanyar live on the slopes of it and Manwë and Varda live on its peak in their halls of Ilmarin. Since it is the tallest mountain in the world, it is said that Manwë could see to all the corners of Arda before the Changing of the World.