blue cave cliff coastline face Great Britain natural nature Pembrokeshire ripples rock sea summer united kingdom wales water welsh wild angry boisterous boulders coast danger rocks rough shore spray spume waves canada cold descend fall freezing frozen glacier ice lake landscape mountain Rockies Rocky Mountains slide snow Cornish cornwall England english island islet isthmus pool rockpool view algae bladderwrack brown exposed green Lofoten Islands low tide norway norwegian orange plants seaweed weed boulder granite gray grey islands land Maddalena mediterranean pink rocky rugged Sardinia shoreline sky distance distant spit beach low ocean sand sandy surf tide Bolivia moon south america toruism valle de la luna valley