Been down here a few times now, really nice place for a mooch about in and A stunning location.
The Pen-yr-orsedd Slate Quarry is located to the north of Nantlle village. An open working, it opened in about 1816 as hillside galleries. Mills were built on three successive levels, the first in 1860 and the next, their first integrated mill, in 1870. The upper mill followed in 1898. Output in 1882 was 8251 tons with 230 men employed. Output was far higher in the 1890s with 613 men employed in 1898. The first connection to the Nantlle railway was by incline via Pen y Bryn (NPRN 33674) until this area was tipped on and direct connection to the railway was made. After closure of the Nantlle line in 1963 road transport was used. The quarry was made up of a series of pits and its most notable feature in the later years was the complex series of four aerial ropeways known as 'Blondins', with Bruce Peebles electrical equipment of 1906. The use of the Blondins gradually ceased, a lorry road being built down into one pit in use in the 1980s. There is also a surviving engine house on the site. The quarry remained in use, as small scale workings from the 1980s until production ceased in about 2000.