Trekkers, tie ’em on. Scotland unveils its first-ever national park this summer, Loch Lomond and the Trossachs National Park, an hour northwest of Glasgow. In the new preserve, the bonny, bonny banks of Britain’s largest freshwater lake meet the forested hills of the Trossachs, homeland of 17th-century outlaw Rob Roy MacGregor. Classic hikes skirt the Eastern Lomond shore and climb the peaks around Loch Katrine.