Erebor
Barfield was also an important influence on Tolkien. In a letter to C. A. Furth of Allen and Unwin in 1937, Tolkien wrote, "the only philological remark (I think) in The Hobbit is...: an odd mythological way of referring to linguistic philosophy, and a point that will (happily) be missed by any who have not read Barfield (few have), and probably by those who have." The reference in question comes when Bilbo visits the dragon Smaug's treasure hoard within the Lonely Mountain: