//Devonian Red Sandstone

Devonian Red Sandstone


These rocks were the first in Wales to be formed above sea level.

These sandstones are the foundations of the Brecon Beacons and the layers of sand were originally deposited by great rivers flowing across extensive planes lying tothe south of a chain of great mountains.

Ancestral fish swam in the rivers, and small plants like simple ferns, grew on the land.

Botanical riches

The soils which have developed on the Devonian Red Sandstone are agriculturally rich.

This Botanic Garden lies over similar sedimentary rocks and on our organically farmed Waun Las NNR, just 10 minutes from here, you’ll find flower-rich meadows grazed by Welsh breeds of cattle and sheep.

Paradise for lower plants

Debris and moisture collects in the crevices of these porous rocks. This, and the rocks’ complex chemistry, has allowed 37 lichens, as well as a number of different mosses, to find a home here.

Some of these flat and crusty lichens are over 15cm wide, and may be over 100 years old.

origin of the devonian red sandstone sampleWhere do these rocks come from?
Heol Senni Quarry, Powys


400 million years old

The Devonian Red Sandstone display at the NBG

Moss and lichens on Devonian Red Sandstone
Moss and lichens on Devonian Red Sandstone

The nearby Waun Las Top Hay Meadow, which sits on Devonian Red Sandstone
The nearby Waun Las Top Hay Meadow, which sits on Devonian Red Sandstone

Typical Devonian Red Sandstone landscape: Welsh black cattle grazing with the Great Glasshouse at the National Botanic Gardens in the background.
Typical Devonian Red Sandstone landscape: Welsh black cattle grazing with the Great Glasshouse at the National Botanic Gardens in the background.