You might look at a map and think about how wonderful a road trip it would be to drive from the top of North America down to the bottom of South America (or vice-versa) on the Pan-American Highway. The problem is that the Pan-American Highway doesn't go all the way- there's a relatively short route that connects the two continents that has never been paved -and might never be. It's called the Darién Gap, and RealLifeLore explains why it's so difficult to build a road through it. -via Digg