Loch Katrine, Trossachs, Scotland. This freshwater loch is the water source for the city of Glasgow. A tourism hotspot in the Victorian period, it still retains its charm today. An enclosed 13 mile cycle path around the loch shores is particularly popular, with a boat trip return for those with weary legs. The old Victorian Pier is still in use and the waiting rooms are now a smart cafe. Highly recommended!