Location Gwynedd, Wales Elevation 389 m Easiest route Hiking Parent range Snowdonia | OS grid SH625462 Translation Welsh language Parent peak Moelwyn Mawr | |
 | ||
Topo map OS Landranger 124, Explorer OL23 Similar Ysgafell Wen, Moelwyn Mawr, Cnicht, Moel Druman, Allt‑fawr | ||
Yr Arddu is a 389m high mountain peak in Snowdonia, Wales (Not to be confused with the 589 metre Yr Arddu to the east of Snowdon). It lies approximately 2.5 km south east of the village of Beddgelert and just over 1 km from the rather more famous mountain Cnicht. It is a rugged hill with widespread rock outcrops and cliffs. A small lake, Llyn yr Arddu, is located on the flanks of the mountain. The craggy nature of the summit is due to the presence of lavas and tuffs (volcanic ash deposits) dating from the Ordovician period when Snowdonia was characterised by numerous volcanic eruptions; Yr Arddu is a particularly good location to see the record of Ordovician volcanism. The Yr Arddu Tuffs may be the earliest eruptive phase of the Lower Rhyolitic Tuff Formation.
Map of Yr Arddu, Penrhyndeudraeth, UK
The whole mountain is a site of special scientific interest designated by the Countryside Council for Wales.
Yr Arddu is commonly approached by a footpath leaving the minor road that links Nantmor to Nant Gwynant but the final 0.5 km has no marked paths.