In ‘Celtic Folklore Welsh And Manx’ (1901), John Rhys recounted the following folktale originally passed down Siân Dafydd of Helfa Fawr, and Mari Domos Siôn of Tyn Gadlas, Llanberis who would probably have been born around 1770.
Specific Location: Snowdon
If you ascend Yr Wyddfa (Mount Snowdon) on the Snowdon Ranger path you will encounter Llyn Coch. Legend has it that this lake is a favourite abode of the Tylwth Teg (Fairy Folk). There is a ‘Fairy Bride’ legend associated with the lake, one version of which goes something like this:
At 1,430 feet above sea level Llyn Llydaw (Brittany Lake) is another sterile glacial lake of Yr Wyddfa (Mount Snowdon) in its eastern valley Cwn Dyli. It has an industrial air about it, and it has the Miners’ track crossing its eastern end by a causeway that was built in 1853 when the lake was lowered.
In ‘Celtic Folklore Welsh And Manx’ (1901) John Rhys describes the following tale he was told concerning a fairy bride in the summer of 1881. ‘An old woman, called Siân Dafydd, lived at Helfa Fawr, in the dingle called Cwm. Brwynog, along the left side of which you ascend as you go to the top of Snowdon, from the village of lower Llanberis, or Coed y Ddol, as it is there called.
In this valley below the south eastern side of Yr Wyddfa (Mount Snowdon), it is said that the Tylwyth Teg (Fairy Folk) live. It is said that one day, a shepherd heard a wailing sound, and he moved a rock where the sound was coming from. When he did this he rescued a Tylwyth Teg who has trapped there. Later, he encountered two old men who thanked him, and gave him a staff.
According to John Rhys in his ‘Celtic Folklore Welsh And Manx’  ‘The following is a later tale, which Mr. Thomas Davies heard from his mother, who died in 1832:–‘When she was a girl, living at Yr Hafod, Llanberis, there was a girl of her age being brought up at Cwmglas in the same parish.
Standing 3650 ft above sea level, Snowdon is the highest peak in Wales, second highest mountain in Britain and is also probably the busiest due to it popularity with hillwalkers.