rockfall warning sign on algarve's cliffs, portugal.

font sign text number yellow brand signage poster red advertising label wall wood banner soil art rockfall warning algarve#39aph39#s cliffs portugal urges beachgoers maintain safe distance cliff prevent potential accidents falling rocks algarve beach nature portugal beach erosion safety warning coastal danger cliffs sign environmental hazard erosion risk hazard alert distance outdoor coastline portuguese coast rock danger rocky safety notice symbol