Today's the day .................... for an added bonus

Arran is a paradise for geologists - with lots of textbook examples of classic geological phenomena. This imposing columnar basalt cliff at the top of the picture, known as The Doon, is the remnant of a pulse of molten granite rock that was squirted into pre-existing horizontally-bedded sedimentary rocks.  This feature is known as a 'sill'. 

I could give you lots of other examples - and go on at length - but, I'm well aware that geology is not everyone's cup of tea!  Suffice to say, for Will and I, it's all an added bonus in what would otherwise be - at the very least - a lovely walk . . . . . . .