Holland's Quarry
This was one of the earliest quarries to be linked to the Festiniog Railway (1839) via the Dinas Branch. It was previously known as Cesail, sometimes Gesail (in effect a mutated form), and was also known as Upper Quarry. It became part of the Oakeley complex in 1878.
It had been opened in 1827 by Samuel Holland Jnr. after he and his father had sold their previous (lower) workings to the Welsh Slate Co. Its output in 1882 was 13753 tons, and it employed 534 men.
In the period when Oakeley was open to the public as the Gloddfa Ganol Mountain Tourist Centre, this long-closed part of the workings was used for guided walking tours (at an extra charge) to which visitors were taken by Land Rover. The walk through the workings, which included a demonstration of lighting by candles alone, led to a viewpoint overlooking Glan y Pwll and Blaenau Ffestiniog.
The area around the main adit was also used as a location for the film First Knight (1995).