America aquamarine blue boulder clean clear cold fast flow natural nature pool pure river rock transparent water conifer forest tree boulders cliffs colours gorge grand canyon layers national park ravine rocks rugged sandstone stone stony trees usa aftermath canada catastrophe dead death destroyed destruction fire lakeside recovering recovery Remains beach coastline Cornish cornwall England english Great Britain ocean sand sandy sea sheltered shore spring tide waves wild caves cliff coast danger green Pembrokeshire view wales welsh cyprus hazard horizon landscape mediterranean reef shoreline current fierce mountain norway norwegian rapid slope strong lake moraine ripples Rockies rocky sunlight Lofoten Islands mountains summer wedge