There is a famous rock face just below Salisbury Crags in Holyrood Park, Edinburgh.
The rock face tells us about the hot volcanic past in Scotland.
It's called "Hutton's Section" after James Hutton who first noticed it.
The pale layered rock is broken and tilted by the reddish-brown massive rock.
Hutton realised the reddish-brown rock must have been molten magma, pushing with force into the older sedimentary rocks.
Edinburgh sits on an ancient volcanic centre.
The volcanic activity happened in the Carboniferous Period.
In this view, Salisbury Crags palisade stands over the city - it is a sill.
On the right is Arthur's Seat, made of four eroded central volcanic vents.
This diagram explains how some volcanic landforms are made.