blue clouds coast coastline Gairloch highlands hull loch mast rock rocks sail sailing scotland sea sky water yacht burn drain drainage flow flowing gentle heather highland pour river stone stones stream trickle white brook cascade damp dark fall moss mossy rapids smooth torrent waterfall wet cloud fell Geological phenomenon hill landscape mountain mountain range Mountainous landforms panorama peak scottish snow battlements castle crenellation fortified granite hilltop Inverness landmark overlooking red top tower walls windows