Nant Ffrancon is a deeply glaciated and visually dramatic valley in north Snowdonia, dropping down to Bethesda between the Carneddau and Gludeiriau Sites of Special Scientific Interest. The valley begins in Cwm Idwal, carrying water from Llyn-y-Cwn to join the Ogwen Valley below the Ogwen Falls on Afon Ogwen. Major features of the area were formed during the last glacial period. During this time, the whole of Snowdonia was veiled in a vast ice sheet that extending outwards forming deep glacial troughs; Nant Ffrancon is one such trough.
Nant Ffrancon is possibly the least agriculturally developed glaciated valley in Gwynedd. The inhabiting wildlife is fascinating to explore and range in locality from the Bethesda area up towards Llyn Ogwen. The minor road on the west side provides a convenient and safe route.
Along the river you may observe Dipper, Common Sandpiper, Grey Wagtail and occasionally Goosander. The neighbouring pines and willow scrub provide sanctuary for a wide variety of other birds including Redpoll, Willow Warblers and Grasshopper Warblers (both summer visitors). Further up the valley, on more exposed ground, Stonechat, Meadow Pipit and Wheatear (summer visitor) are commonly seen. The aromatic low shrub, Bog Myrtle, carpets much of the lower valley floor shrouding the winter grassland in a purple haze. Near the head of the valley runs a nature trail improving accessibility to the river which is frequented by Otter and Water Vole. The small woodland by Ogwen Cottage is ideal for birds, boasting varieties such as Redstart, Spotted Flycatcher (both summer visitors) and Siskin.
Culturally and historically the surrounding area is richly endowed with plenty to offer including the extensive remains of slate quarries and tips; ancient monuments of the Neolithic and Bronze Age; Iron Age hill forts and medieval settlements. Some examples of early fields and dwellings can be seen east of LLanllechid, with certain areas of Cwm Caseg and Moel Faban marked by ancient settlements and enclosures.
There is a car park at Ogwen Cottage, located next to the A5 between Bethesda and Capel Curig, as well as Ogwen Car Park located within Bethesda.