The Undying Lands, which until that time had been part of the World, were removed forever from the reach of mortal Men, though the Cats could still sail West an

The Undying Lands, which until that time had been part of the World, were removed forever from the reach of mortal Men, though the Cats could still sail West and come there, if they would. It is to the Undying Lands that the White Ship sails at the end of 3rd Age (25 million years ago). I like to think that the cats went off-world when the cat oracles foresaw that the age of man was coming.