"I should know better Dougie, I have a B.Sc. in Chemistry, (though I did look at a Higher Chemistry paper recently and struggled to answer any of the questions ! :-)... makes the image more fascinating, to see the real colour of the sandstone too. Thanks for sharing that !"

"Cracking pics Ian. At the risk of being a geek, it is the copper content of this brass plaque that is protecting the stone. Exposure to air and water creates oxidisation of the copper creating a natural fungicide called Copper Sulphate - a highly effective moss and lichen killer. The chemical residue gently washes down the surface of the stone during rainfall preventing the attachment of new lichen growth. It's a trick that used to be used on north facing slate roofs .....which is why I know about it. ;o)"

"great photos of daddy and we loved the eagle and ptarmigan hole!!!"

"Could be misstaken for somewhere exotic like Scotland."

"Let's haaave it!"