In America, we hear a lot about "The Border," the line of barbed wire and desert separating Mexico from Texas, New Mexico, Arizona and California. That imaginary line -- imaginary in the sense that it has been drawn and redrawn and has no real geological basis -- helps define what it is to be American exactly as similar lines help define the nationalities of people from all over the world.
Unfortunately, borders are not always about positively defining a community. They can also be about keeping people who aren't part of our community or country, at bay. Well-traveled tourists have been through these checkpoints, where inspection takes on racial, political and violent overtones. Still, as fraught as many crossings are, there are really only a handful of international borders that travelers would do well to avoid at all costs.
The world's most dangerous borders sit between rival states, countries with long simmering resentment and economically uneven nations. They also run through jungle and desert, landscapes that blur lines and provide additional threats of their own.