I'm curious about things like the recurrent laryngeal nerve, which runs all the way down, under the aortic arch, then back up to the vocal cords. In early vertebrates, bodies were configured differently, and so the nerve took a direct route. Over millions of years as anatomy changed and necks elongated, the course of the nerve remained the same. Now it has a very inefficient course.
Are there other examples in humans like this? Anatomical curiosities that made sense at one point, but are now "outdated".