Soldiers from rival North and South Korea eye one another across a thin strip of no man's land that - just barely - keeps their armies apart. The tension, they insist on both sides, is palpable.
So what's with the North Korean gift shop selling "See you in Pyongyang" T-shirts for 12 euros apiece?
Or the South Korean border towns complete with amusement parks, souvenir blueberry-flavoured North Korean liquor and a Popeyes chicken outlet?
Is the Demilitarised Zone between the two Koreas the world's most dangerous place, or a tourist trap? Sometimes it's hard to tell the difference.
"There is always a threat to safety here," North Korean Lieutenant Colonel Nam Dong Ho warned a handful of foreign visitors who came to his side of the frontier early this week.
The usual tensions were augmented by this week's unusually specific vow by the North to turn the South's government into ashes "in three to four minutes," along with speculation Pyongyang might hold its third nuclear test.
Nam reassured his guests that two North Korean soldiers would accompany them during the tour of the tense front line. But the often-smiling pair of soldiers didn't appear the slightest bit worried.
Nam began his tour pointing out highlights on a hand-painted map of the DMZ, the four-kilometre-wide space that divides the two armies, and Panmunjom, the once-obscure farming village that now hosts the "Joint Security Area" overseen by both sides.
It was in Panmunjom where US and North Korean forces negotiated and eventually signed the 1953 truce that ended fighting in the Korean War.
The two sides technically remain at war, and their frontier is a deeply dangerous place with hundreds of thousands of soldiers stationed nearby, backed by artillery batteries and vast fields of land mines. US war planners worry that incidents along the frontier could spark a major conflict.
But Panmunjom is where the two sides come into contact, and few soldiers are seen during the tours here.
There are buildings on both the North and South Korean sides of the front line, with a handful of simple structures straddling the concrete strip that marks the exact cease-fire line.
Today, the buildings are used infrequently, said Nam, such as when North Korea hands over remains of Westerners killed during the Korean war.
So who does come here?
Tellingly, Nam's initial briefing was right next to the gift shop, where visitors can pick up North Korea T-shirts or small flags for two euros apiece. Don't even think of spending North Korean won - foreigners can only use hard currencies here.
The charge to visit the DMZ on the North Korean side is US$20 for foreigners, a serious amount in a country where per capita income is less than US$2000 per year. Ordinary North Koreans don't often visit.
In South Korea, a nation which once lagged badly behind the North economically, but which has since become Asia's fourth largest economy, the charge is US$75.
Fittingly, the more expensive tour on the South Korean side starts at the Lotte Hotel, one of Seoul's fanciest.
Tourists face some scary paperwork: They must sign a document acknowledging they're visiting "a hostile area (with the) possibility of injury or death as a direct result of enemy action."
The bus heads northward from congested, modern Seoul to sparser areas on a highway that later meets up with the wide Han River.
Soon, the highway is separated from the water by a high fence topped with rolled razor wire. The armed sentries are on the lookout for North Korean infiltrators, says the tour guide, a middle-aged South Korean woman who calls herself Laura. Throughout the day, Laura uses her microphone to remind her tourists about the dangers they'll soon encounter.
She need not bother. The menace is hard to miss.
The tour takes visitors by a small monument at the site of the 1976 'Axe Murder Incident,' where two American officers were hacked to death by North Koreans during a fight that began as a dispute over US efforts to trim a tree. Occasional exchanges of gunfire also occur along the border, as recently as October 2010.
"It makes me uncomfortable, but not uncomfortable enough not to come up here and check things out for myself," said Robert Winn, 34, a tourist from Anchorage, Alaska, who was visiting a town near the border.
At the dividing line, few tourists speak as they look at the South Korean soldiers facing North Korea - tall uniformed men in fierce, rigid poses, hands formed into fists, shoulders thrown back, mirrored sunglasses covering their eyes.
The only visible North Korean soldier stands with binoculars on steps outside a building on the other side. Laura assures the group that inside the building "there are many eyes, and they're taking pictures of everything we do."
It feels tense, certainly, but the Western tourists grumble about what they describe as a strong element of theatre.
"When the South Korean and North Korean soldiers are standing next to each other, I wonder how much they want to just start talking to each other and find out what they did the night before," said Tami Richter, 34, an American who lives part-time in South Korea.
After visiting the dividing line, it's time to shop and eat. Tour operators take their guests to a gift shop filled with garments and goodies, many stamped with DMZ logos. North Korean blueberry liquor is the top seller.
Eventually, the tourists file back onto the bus with plastic bags filled with T-shirts and booze.