Gorse flowers are starting to clothe the slopes of Arthur’s Seat in gold but probably few walking below Salisbury Crags realise the geological significance and importance these rocks are.  James Hutton had overturned current beliefs about the formation of the Earth in 1788 and managed to persuade the quarrymen who had been quarrying the crags for paving stones (including for London) to leave a part of the rock which was no use for paving . Known as Hutton’s Rock (extra)  it seems to glow in the middle distance in the late afternoon sunshine.