Middle-earth is the main fictional region in J.R.R. Tolkien’s The Lord of the Rings. It is the setting for places such as the Shire, Rohan, Gondor, Mordor, and the Misty Mountains.
The name translates Tolkien’s use of the Old English term middangeard, a word for the inhabited world. In Tolkien’s mythology, Middle-earth is not another planet; it is a region of Arda, the larger world created in his legendarium. The stories take place during different ages of that world.
The Lord of the Rings is set near the end of the Third Age. The War of the Ring affects many peoples across Middle-earth, from hobbits in the Shire to the kingdoms of Men and the remaining Elves. This broad geography gives the quest its changing landscapes and political dimensions.
Valinor, Númenor, and Beleriand are also important Tolkien locations, but they are not interchangeable with Middle-earth. Valinor lies in the Blessed Realm, Númenor is an island kingdom, and Beleriand belongs mainly to the First Age.