We visited Pillar Rock using the High Level Route from Black Sail. The most exciting part is called the Shamrock Traverse, as shown in the bottom picture (best kept for a dry day). I found these rocks that are layers of volcanic ash, a reminder of the violent geological past in these parts. First notice how many layers there are. I wonder how many years these represent. Would it be in the millions? Then the banding. Different types of ash? It's a bit like tree rings except that they are not put down regularly so you can't guess the length of time. There is a great picture of the 2010 Icelandic eruption on APOD today with an explanation about why it produced so much ash. http://apod.nasa.gov/apod/astropix.html (if you are reading this tomorrow or beyond, you'll need to click on "Archive" and get the picture for 20 April 2014)
