J.R.R. Tolkien calls the continent containing the Shire and Mordor Middle-earth.
Middle-earth is the inhabited central region of Arda, Tolkien’s broader fictional world. It includes locations such as Gondor, Rohan, Mirkwood, Rivendell, and the lands surrounding Mordor. The term is not the name of the entire universe; Valinor and other regions lie elsewhere in Arda.
Tolkien adapted the expression from older Germanic and English concepts, including Old English middangeard and the Norse term Midgard. In his writings, Middle-earth is a translation of a historical mythological idea rather than simply a synonym for a planet called Earth.