In J.R.R. Tolkien’s Middle-earth, Mordor is the realm ruled by Sauron.
Mordor lies in the southeast of Middle-earth and is described as a land of volcanic mountains, ash, and barren terrain. Its name is commonly translated from Tolkien’s invented languages as the Black Land or Land of Shadow, reflecting its association with Sauron.
The land contains Mount Doom, the volcano where Sauron forged the One Ring. The Ring can be destroyed only in the fire in which it was made, so Mordor becomes the destination of Frodo and Sam during the central mission of The Lord of the Rings.
Mordor is not the same place as Isengard, which is the fortress associated with Saruman, or Gondor, the human kingdom that opposes Sauron. These locations are connected by the war but have different rulers and roles.