I'm Dutch (duh) and for a small country we have a rel. long coast line. I mean most folk, if not all, in Holland been to the coast and the sea at some stage in their youth or later on.
Um, little history telling?...
Our/ my country is p/m half (of it) below sea level and our ancestors who experienced flooding quite often got really fed up with this and thought of a solution for this, losing houses, lives, cattle and crop.
Um, not stupid they came up with a simple, yet perfectly working, solution; they put up barriers of cane or wood, creating a low line (wall like) barrier 10/20/30 meters inland where with normal high tide the water would stop going further. The wind does the work basically from there, leaving fine sand behind such a barrier, and gradually creating a dune that became higher and higher after repeating that process. This is absolutely true and folks started doing this for maybe over a thousand years.
Thus our coast line is mostly man made and mainly sandy dunes. Nowadays we use rocks to make barriers a lot but the old ones still work fine 95/100 of the time.
~
Stupid question maybe after this but in which part of the world do you live?