Goon Gumpas

(I just wanted to say that)

The post-industrial landscape at Wheal Maid.  Here was, in the early 1800s, the richest copper deposit In the world.  The mines also produced tin and, later, arsenic.  Cheaper sources of copper and the huge cost of pumping water from the deep shafts brought about the closure of many mines in the late 1800s.  

These and other minerals contribute to the fantastic colours in the rock and the tailings lagoons.  The area is highly contaminated with arsenic so raising dust by mountain biking over it would be very unwise. 

Arsenic was used, amongst other things, as a pesticide, to colour sweets green and in wallpaper pigments.  In a smoggy atmosphere these compounds in wallpaper reacted with acidic fumes to produce the highly toxic arsine gas.  (I have a vague recollection of people being killed by wallpaper in a film or TV drama of many years ago.)