Gyrn Ddu is a summit in the Llyn Peninsula region or range in Wales, United Kingdom of Great Britain....
The Deweys are a classification of hill by height. According to Wikipedia :A Dewey is a hill or mountain in England or Wales over 500 metres (1,640 feet) in elevation, but below 2,000 feet (609.6 metres), with a relative height of at least 30 metres (98 feet). The list was compiled by Michael Dewey and published in his book Mountain Tables. We’ll be adding a list of Dewey hills here soon!
There are 426 Dewey hills as of September 2017.
Changes Pending to the lst: 19202 Esgair Greolen (31A) replaces 3463 Bryn Yr Wyn