back forty

Etymology
, meaning “back side of a farm”. In the (1860s–), farmers were granted a quarter section; a section was nominally 1 square mile containing 640 acres, a quarter section was 160 acres, and the quarter section was itself subdivided into four quarter-quarter sections of 40 acres each: two front forty and two back forty. Compare, , , and.

Noun

 * 1)  The remote part of a farm.
 * They couldn't contact the farmer right away because he was out plowing the back forty
 * 1)  The most remote or inaccessible part of any place.

Synonyms

 * See: Thesaurus:remote place