This double-decker, sightseeing ship is showing tourists the beauty of Loch Lomond. This 269 square mile loch, Scotland’s largest, was immortalized in the famous 1841 song “The Bonnie Banks o’ Loch Lomond.” As the boat passes by Inveruglas Isle, the tour guide explains how it contains the ruins of the Clan MacFarlane castle. The citadel was destroyed circa 1654 by Oliver Cromwell’s soldiers.