Most people have made this mistake of thinking Middle-earth is a particular kind of earth or is another planet of the science fiction sort but it's just an old fashioned word for this world we live in, as imagined surrounded by the Ocean.
J. R. R. TolkienAnd so it was settled. Sam Gamgee married Rose Cotton in the spring of 1420 (which was also famous for its weddings), and they came and lived at Bag End. And if Sam thought himself lucky, Frodo knew that he was more lucky himself; for there was not a hobbit in the Shire that was looked after with such care. When the labours or repair had all been planned and set going he took to a quiet life, writing a good deal and going through all his notes. He resigned the office of Deputy Mayor at the Free Fair that Midsummer, and dear old Will Whitfoot had another seven years of presiding at Banquets.
J. R. R. TolkienI come from under the hill, and under the hills and over the hills my paths led. And through the air. I am he that walks unseen. I am the clue-finder, the web-cutter, the stinging fly. I was chosen for the lucky number. I am he that buries his friends alive and drowns them and draws them alive again from the water. I came from the end of a bag, but no bag went over me. I am the friend of bears and the guest of eagles. I am Ringwinner and Luckwearer; and I am Barrel-rider.
J. R. R. TolkienThe way is shut. It was made by those who are Dead, and the Dead keep it, until the time comes. The way is shut.
J. R. R. TolkienI must indeed abide the Doom of Men whether I will or nill: the loss and the silence. But I say to you, King of the Numenoreans, not till now have I understood the tale of your people and their fall. As wicked fools I scorned them, but I pity them at last. For if this is indeed, as the Elves say, the gift of the One to Men, it is bitter to receive.
J. R. R. Tolkien