Cadair Idris

Cadair Idris
Llyn Cau within the steep rock walls of Craig Cau. Penygadair, the summit of the mountain, is to the right
Highest point
Elevation	893 m (2,930 ft)
Prominence	608 m (1,995 ft)
Parent peak	Aran Fawddwy
Listing	Marilyn, Hewitt, Nuttall
Naming
Translation	Chair of Idris (Welsh)
Pronunciation	Welsh: [ˈkadair ˈɪdrɪs]
Geography
Location	Gwynedd, United Kingdom
Parent range	Snowdonia
OS grid	SH711130
Topo map	OS Landranger 124, Explorer OL23
Climbing
Easiest route	Hike

Cadair Idris or Cader Idris is a mountain in Gwynedd, Wales, which lies at the southern end of the Snowdonia National Park near the town of Dolgellau. The peak, which is one of the most popular in Wales for walkers and hikers, is composed largely of Ordovician igneous rocks, with classic glacial erosion features such as cwms, moraines, striated rocks, and roches moutonnées.

Cadair Idris means 'Idris's Chair'. Idris is usually taken to be the name of a giant or, alternatively, it may refer to Idris ap Gwyddno (or Gweiddno), a 7th-century prince of Meirionnydd who won a battle against the Irish on the mountain. Idris ap Gwyddno was in fact referred to as Idris Gawr ("Idris the Giant") in some mediaeval genealogies of Meirionydd.

The basic meaning of the word cadair (Middle Welsh/Early Modern Welsh kadeir or cadeir) is 'seat, chair' (borrowed from the Latin cathedra 'chair'). In place names cadair can mean 'stronghold, fort, fortress' or 'mountain or hill shaped like a chair'. The spelling cader represents a spoken variant of the standard form cadair.

It appears that Cadair/Cadeir Idris is the form used in the earliest Welsh-language sources. In a poem in his own hand in the second half of the fifteenth century, the poet Lewys Glyn Cothi wrote 'Dros gadair idris gedy' ('and then over Cadair Idris'). Around 1600, John Jones of Gellilyfdy referred to 'y mynydh neu bhan neu bhoel a elwir Cadeir Idris' ('the mountain, peak or hill known as Cadeir Idris'.