According to Tolkirn himself, based the race of Númenóreans, the noble race of Men of the First Age of Middle-Earth on the Egypts and their monumental tombs. Indeed, it is possible to see similarities between the Noirinan, the Valley of the Tombs of Númenor and the Valley of the Kings in Egypt. 

The city of Rome could somehow be compard to the citadel of Minas Tirith, in Gondor. Both have an imperial history, are located in the southern area, have a sea-based economy, have massive walls protecting them, are built on a hill and have seven concentric walls that make them (nearly) invulnerable.

Tolkien wrote in a letter in 1960 that "The Dead Marshes [a place north of Mordor] and the approaches to the Morannon [an entrance to Mordor] owe something to northern France after the Battle of the Somme". In both cases, these are places where a great number of people died while fighting, and perhaps the sounds of artillery, bombs and so on can be compared to the drums used by orcs and goblin in the dwarf city of Moria before attacking the Fellowship.

The name of the Hobbit-hole where Bilbo Baggins, the main character of The Hobbit, lived, "Bag End", was actually the real name of the Worcestershire home of Tolkien's aunt Jane Neave here in Dormston.