The Demilitarized Zone (DMZ) between North and South Korea is an intensely fortified strip of land, 248 kilometers long and 4 kilometers wide, possibly the most heavily armed place on Earth. It features two million mines, barbed wire fences, tank traps, and tens of thousands of troops from both sides. Despite this, recent incidents of North Korean soldiers crossing into South Korea have been attributed to overgrown foliage obscuring the demarcation line markings.