Twisted Sisters (Texas)
Credit: Josh Noel / Chicago Tribune / Getty Images

Think Texas is flat? Guess again. The "Twisted Sisters" or "Three Sisters" loop undulates through a 100-mile loop of good ol' fashioned Texas Hill Country. While it's natural to gawk at the gorgeous terrain and the nearby bodies of water, you'll want to keep an eye on the road, which is notorious for making minced meat of inattentive drivers with its decreasing radius and off-camber turns.