heartland

noun

1. the part of a region considered essential to the viability and survival of the whole, especially a central land area relatively invulnerable to attack and capable of economic and political self-sufficiency.
2. any central area, as of a state, nation, or continent: a vineyard in California’s heartland.

noun

1. the central region of a country or continent
2. the core or most vital areathe industrial heartland of England