When flying into Dallas-Fort Worth, the cities seem to shoot up out of nowhere from a giant prairie. Looking closely at the ground you will see many of the roads leading into the cities curve and bend, following no discernable logic at all. Why are they like this? Because back when Dallas was primarily a ranching town those were the paths the cattle would follow as they were driven into town. They would walk the long way around hills, cross rivers only at the low points, and follow a path of least resistance the whole way there. Over time people started following the same paths, and eventually they paved them and made them permanent. So now the town has a bunch of inefficient roads just because that was the way they had always been. (link)