Edinburgh, Scotland

Arthur's Seat is Edinburgh's highest hill, visible for miles around. The rocky slopes and cliffs of Arthur's Seat and Salisbury Crags are part of Holyrood Park and provide a spectacular natural backdrop to the city. The park, Edinburgh's wildest and biggest open space, is a place of sanctuary from the crowded streets and a piece of countryside within the city limits.

Arthur's Seat is an extinct volcano, which erupted around 340 million years ago. At that time, Scotland was a very different place, located close to the equator. The rocks of Holyrood Park give us some clues about what it was like in the past - there are sandstones formed in shallow seas and laid down by rivers, layers of volcanic ash created by many explosive eruptions of the ancient volcano, and lava flows representing quieter times. 

The volcano has been eroded so that now less than half remains, and this allows us to walk into the heart of the volcano and see rocks created underground.

Holyrood Park holds a special place in the history of science, for it was here in the late 18th century that James Hutton found evidence to support his theories about the workings of the Earth. At Salisbury Crags, he observed igneous and sedimentary rocks and understood that they had been formed at different times by different processes. He suggested that the Earth was very old, and continually changing; a startling new idea that changed forever the way people thought about our planet, and influenced other scientists such as Charles Darwin. James Hutton is now recognised as the 'father of modern geology'.

Text courtesy of Angus Miller at Geowalks.