Erratic

Had an epic 90 mins or so hooning around in the windy wind on Loch Venachar then decided I was pushing my luck and should probably quit while I was ahead. 
Had some time to spare so headed off to run up a cool looking hill.
 Geology says it's an erratic from the last ice age. 
Local legend says the Fingalian giants were throwing stones to see who was strongest and Samson lobbed this one from Ben Lawers (21 miles away) and won.