polders are areas who once used to be sea, but with the years became land.there is pretty fertile soil, used to grow the famous polder bintjes...potatos for french fries.
polders are mostly below sealevel, protected against the sea only by pretty vulnerable dunes. if people go on behaving like they wouldnt cause a climat change, caused by driving their big cars, the sealevel will rise more and soon the polders will be sea again.
i live in the polders. i love them because here is always fresh sea breeze...all is extrem flat, which ''creates'' a very large sky.
with good weather you can see easily 1o miles in all directions without seeing any big obstacle.