heartland (n.)

• airspace
• area
• belt
• confines
• corridor
• country
• department
• district
• division
• environs
• ground
• hinterland
• inland
• interior
• land
• midland
• milieu
• neighborhood
• part
• parts
• place
• premises
• quarter
• region
• salient
• section
• soil
• space
• terrain
• territory
• vicinity
• zone