blue cliff coastal coastline danger exercise footpath grass Great Britain green path Pembrokeshire plants rocks sea shore steps trail travel Trek united kingdom view wales walk wander water welsh autumn Betula birch bracken color colour countryside England english fall fence forest gold nature rural russet sunlight Sussex tawny track tree trunks woodland cloud dramatic field landscape meadow sky spring bridleway natural peace tranquil trees woods hike hillside mountain norway norwegian slope snow steep wild cars dark eerie filtered glow gray grey lights mist misty power-lines road roadside roadway street traffic traffic-lights. trees vehicles