In J.R.R Tolkien's, The Lord of the Rings: The Fellowship of the Ring. Frodo sings a song at Bree, that is supposed to be a precursor to the nursery rhyme, 'Hey Diddle Diddle'.
Is there anything else that exists in Tolkien's Middle-Earth work that is designed to be an earlier version of something that exists/existed?
(For example, are there certain cities or land marks that still exist today?)