When was the last time a volcano erupted in Britain?

The last major volcanic activity in Britain was roughly 55 to 62 million years ago during the Palaeogene period, when the North Atlantic was opening up. There were also earlier volcanic episodes going back hundreds of millions of years, but nothing has been active in recorded human history.

Are the Lake District mountains volcanic?

Yes, much of the Lake District's dramatic landscape is carved from ancient volcanic rocks, including thick layers of volcanic ash (tuff) from violent eruptions about 450 million years ago. Scafell Pike, Helvellyn and the central fells are all built from these volcanic deposits.

What's the difference between a volcanic plug and a sill?

A plug is magma that solidified inside a volcano's vent and got left standing when everything around it eroded away—like Edinburgh's Castle Rock. A sill is a horizontal sheet of magma that forced its way between existing rock layers underground but never reached the surface, like the Whin Sill that Hadrian's Wall follows.

How the Hills Got Here

What Volcanoes Left Behind in Britain

Extinct volcanoes left lava flows, ash deposits, intrusions and collapsed calderas across parts of Britain. Their resistant volcanic rocks now form familiar crags, ridges and mountain landscapes.

8 September 20266 min read