The Green Mountains -- Extending the entire length of Vermont, a bony spine stretching from Massachusetts to Canada, this chain of forested hills and (mostly) low mountains allows for great hiking and skiing, scenic back-road drives, fantastic inns, and superb cycling. The apples and the maple syrup here taste pretty good, too; be sure and stock up.
Lake Champlain -- Pastoral and scenic, the region of Vermont that forms the eastern shore of Champlain is filled with idyllic drives and a sense of gracious openness -- along with lots of dairy cows and great views of the Adirondacks.
Northeast Kingdom -- This is Vermont at its most remote and "lost in time." The state's northeastern counties are rugged, hilly, and unpolished, but there are some improbable grace notes such as the little city of St. Johnsbury: It has not one but two excellent museums. You can also find great cheddar cheese right at the source.
