Source of Conwy Castle stone
Constructing the castle and town walls at Conwy in the late 13th century needed a lot of stone, and this is where most of it came from.
The opening by St Agnes Road leads to the upper level of the quarry where stone was excavated. To get a better view, walk through the opening and turn left along the public footpath which rises and curves around the edge of the old quarry. St Agnes Road runs through the centre of the quarry site. More stone was excavated from the area below the road.
The castle and town walls were mostly made of grey Silurian grit, which is hard and durable. Sandstone was brought in to line the edges of doorways, windows and loopholes. It was easier to carve the required shapes from sandstone than from the local Silurian grit. The castle and walls were off-white when new, having been rendered and limewashed. The weather eroded the render centuries ago, leaving the grey Silurian grit to define the town’s appearance.
The Silurian geological period, more than 400 million years ago, gets its name from the Silurian System devised by Scottish geologist Roderick Impey Murchison (1792–1871) after he realised that fossils could tell us how some of the Earth’s land was formed. He reached this conclusion after mapping the geology of South-east Wales and neighbouring areas of England. He chose “Silurian” after the Silures, the British tribe which inhabited Gwent and Glamorgan when the Romans invaded.
With thanks to Llew Groom, of Aberconwy Historical Society
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