heartland          
noun [ C, often plural ] uk/ˈhɑːt.lænd/ us/ˈhɑːrt.lænd/
 (国家或地区的)腹地
the central part of a country or area
  the heartland of America 美国腹地 
  中心地区,重要地区
the part of a country that is most important for a particular activity, or where a political party has the most support
  the old industrial heartlands 旧时的工业重地 
UK the Labour/Tory heartlands 工党/保守党的领地