From the 19th century, so-called groynes were built to protect European coasts. These structures were initially constructed with timber or rocks, and subsequently also with materials such as concrete. They were intended to prevent the erosion of coastal sand.
Groyne near Mundesley (Norfolk, Great Britain), colour photograph, August 2008, photographer: Michael Maggs; image source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Groyne_at_Mundesley,_Norfolk.JPG, Creative Commons Attribution ShareAlike 3.0 Germany (CC BY-SA 3.0), https://creativecommons.org/licenses/by-sa/3.0/de/deed.en.