heartland.

Synonym of heart (“the seat of the affections or love”).

Also in the plural form heartlands: The interior part of a region, especially when contrasted with coastal parts or when regarded as particularly powerful or significant.

Also in the plural form heartlands: In the geopolitical theory of the English geographer Halford John Mackinder (1861–1947): the interior of the world island comprising north-central Eurasia regarded as politically powerful.

Also in the plural form heartlands: Residential districts and planning areas outside the city centre; the new towns of Singapore collectively.

Also in the plural form heartlands: The states in the centre of the United States, chiefly regarded as politically and socially conservative; also, the people living in such states collectively.

Also in the plural form heartlands: A region or part of a region particularly associated with or significant for a characteristic, such as an activity, a faith, support for a political party or other organization, etc.

The home counties are the Conservative heartland.

We stayed in the heartland of the French wine-growing regions.