Parts of a country behind the coast or a river's banks

One word substitute is Hinterland.



Isthmus: a narrow strip of land with sea on either side, forming a link between two larger areas of land.

Archipelago: an extensive group of islands.

Hinterland: the remote areas of a country away from the coast or the banks of major rivers.

Swamps: an area of low-lying, uncultivated ground where water collects.