Heavily armed military zone? Tourist attraction? Why not both!
The Korean Demilitarized Zone runs right across the Korean peninsula, on or near the 38th parallel. It’s about 250 km long and 4 km wide, and right inside this zone is a little place called the Joint Security Area (or Truce Village). The village is a collection of just a few buildings, where diplomatic meetings between the two Koreas are held. It’s also where North and South Korean guards stand facing each other all day, staring each other down and awaiting the next invasion. It’s still a war zone. And you can go visit! Because weirdly, the Joint Security Area has become a popular-ish tourist attraction. Tourism companies organize visits to the village so that you can see the grounds, tour the buildings, get within an arm’s length of the guards. It draws about 100,000 tourists a year. Here’s a picture of the South Korean guards in action.

Here’s a closer shot of a South Korean soldier, guarding the door to North Korea.

The South Korean guards seem pretty severe and intimidating — with round helmets and black sunglasses. According to Wikipedia, the guards are required to be at least 5’8 and have a black belt in martial arts. No little guys defending the border.
Which brings to mind the claim I once read that North Koreans, because of years of famine and deprivation, are on average almost half a foot shorter than their South Korean counterparts. I think I first read this in a Christopher Hitchens column, so I’ve always taken it with a grain of salt. But this Wall Street Journal article confirms at least some disparity in height — though less than Hitchens claimed. Here’s a picture of the North Korean guards.

Behind the guard in the centre, you can see the physical border between the two Koreas. Talk about a clear line of demarcation.
There are some really neat videos on YouTube of visits to the JSA. Here and here are links to a couple. Although the South Korean guards seem to maintain a stern stance and expression in all the videos, the North Koreans can sometimes be seen waving at cameras and smiling. The North Koreans have also been accused of making rude gestures, spitting, and generally taunting the stoic South Koreans. Much like the hilarious French taunters from Monty Python and The Holy Grail. The National Geographic article reports that the North Koreans even once chopped inches off the legs of the South Koreans’ chairs in advance of a diplomatic meeting so that the South Koreans would look “small and silly.”
As for the rest of the DMZ? Well, because human inhabitation in the region has been pretty much nonexistent in the last half-century, the zone has become an amazing wildlife reserve. Endangered and near-extinct species have found sanctuary right between the warring Koreas. There’s a good metaphor there.