what would possibly exist in the farthest east?

[Faramir Jones]

According to Akallabêth, published in The Silmarillion, due to the Ban of the Valar

the voyages of the Dúnedain in those days [most of the Second Age] went ever eastward and not westward, from the darkness of the North to the heats of the South, and beyond the South to the Nether Darkness; and they came even into the inner seas, and sailed about Middle-earth and glimpsed from their high prows the Gates of Morning in the East.

If those Gates were anything like how they've been represented by some artists, including Roger Garland, the sight of them must have been well worth the voyage!