Fenland and Polder

Fenland noun - Low-lying wet land with grassy vegetation; usually is a transition zone between land and water.

Polder and fenland are semantically related. In some cases you can use "Polder" instead a noun "Fenland".

Polder noun - Low-lying land that has been reclaimed and is protected by dikes (especially in the Netherlands).

Fenland and polder are semantically related. You can use "Fenland" instead a noun "Polder".