The hinterlands are affectionately called "the sticks," or the "boonies," short for "boondocks." Use it to specify an area that is far away from a city or town, or even civilization as we know it. Cell-phone reception and cable television aren't guaranteed.
The noun hinterland comes to the English language via Germany: hinter is "behind" + land is, well, "land." It actually refers to the land lying inland — or behind — an ocean coast or river shore, which is why backwaters and hinterlands are used interchangeably. Use hinterlands when you want to make fun of an area's backwardness, or to celebrate its natural beauty: "Coming from the unspoiled hinterlands of Louisiana, she found it hard to adjust to the sights and sounds of the big city."