Twin Erratic boulders high above Nant Ffrancon valley, Snowdonia National Park (Eryri), North Wales, United Kingdom

snowdonia nant ffrancon erratic boulders rocky landscape mountains nature welsh scenery hiking valley outdoor dramatic sky greenery geological formations tourism travel eryri scenic views wildlife tranquility rugged terrain elevation cloud cover exploration natural beauty environmental adventure picturesque earth sciences rock formation heritage geology moss attractions steep slopes countryside fresh air