Giant quarry pit, Dinorwig slate quarry
This deep pit was formed as quarrymen followed the vein of valuable roofing slate further and further down. Please stay on the footpath and do not cross the fence.
According to former quarryman John Roberts, the pit was known as Sinc California. Sinc was the quarrymen’s term for slate workings in a pit.
The cliff to the left, as you view the pit from the path, was the edge of the Braich department of the quarry (braich = arm). Quarrying at Braich began in 1822. The path rises to pass through a cleft which was opened in the last quarry’s later years. Lorries passed through it to reach the Garret department, on the far side.
The haul road superseded a short tunnel for narrow-gauge trains. You can see the tunnel’s southern portal from the path. The railway on this level was a useful connection between the quarry’s two main departments. Underneath it was a railway tunnel on the next level down, known as California. The lower part of the quarry pit was accessed through that tunnel.
On the clifftop you can see a tall stone tower, once used for an aerial ropeway. Higher up the mountain beyond the tower were other pits, including Sinc Matilda. The Matilda area of the quarry was named after the wife of quarry owner Thomas Assheton Smith. Work began here on their wedding day, 17 October 1827.