Wales’ Story, Set In Stone
Wales has one of the most fascinating geological histories in the world.

Where our rocks came from
1 Pre-Cambrian Rock 615 million years old
2 Cambrian Rock 510 million years old
3 Ordovician Volcanic Rock 475 million years old
4 Ordovician Spotted Dolerite 475 million years old
5 Ordovician Rhyolite 480 million years old
6 Silurian Rock 430 million years old
7 Devonian Red Sandstone 400 million years old
8 Dolomitic Carboniferous Limestone 330 million years old
9 Carboniferous Limestone 330 million years old
10 Upper Carboniferous Sandstone 310 million years old
11 Carboniferous Millstone Grit 325 million years old
The Rock of Ages display is packed full of clues about this history. Look closely and you’ll discover evidence of volcanic islands, the extinction of animals, dramatic changes of climate and the emergence and drowning of continents.
Along the way you’ll pass through over 300 million years of Welsh history.
Life on Stone
You’ll also discover how geology has had a huge effect on the plant life of Wales. Over 75 species of lichen have colonised these rocks. Along with mosses, weather and water, lichens help to break up rocks and turn them into soil.
Wales Rocks
Wales has played a major part in furthering the world’s knowledge of geology. One of the founders of modern geology, Adam Sedgewick, named the Cambrian geological period after studying rocks from Wales, whilst the Ordovician and Silurian time periods are named after ancient Welsh tribes.
Geology has also brought great prosperity to Wales – the land’s gold, copper, coal, slate, sandstone and limestone have all been quarried and mined on a large scale.