A North and South Korean guard exchange stares at the truce village of Panmunjon, only 34 miles north of Seoul. Photo from Reuters/Lee Jae-Won.

Sandwiched between two of the world's most formidable military forces is an emerald-shaded ribbon of land, two and half miles across by 155 miles long, a refuge for animals long thought to have disappeared from much of the rest of Asia.

The area separating North and South Korea, between thousands of pieces of artillery, tanks, and soldiers, the most heavily militarized piece of land on the planet, also has a tender, green side.

As a consequence of years of isolation and human neglect, the De-Militarized Zone, universally known as the DMZ, has now become one of the world's best-preserved havens for endangered animals, a success story for nature even amid continued diplomatic failures between the northern and southern states of a long separated single nationality.

July 27 marks the 59th anniversary of the signing of the armistice ending the Korean War between South Korea, with allied forces from the United States and United Nations, and North Korea, allied with China, and supported by the Soviet Union. Casualties from both sides (including both dead and wounded) are more than 2 million for the military and more than 2.5 million for civilians. No formal peace treaty has ever been signed between the two Koreas.

When the two forces signed their armistice in 1953, the front lines, which hovered close to the 38th parallel that divided the two before the war, became a Military Demarcation Line, or de facto border; the two kilometers (1.2 miles) on either side of that line were vacated; and the entire area was designated a "demilitarized zone".

Photo of the DMZ from space, from NASA Earth Observatory. The DMZ can be seen as the green line separating yellow-grey areas of human cultivation in the west, extending into more mountainous areas in the east. Seoul is the large light-grey mass in the image's bottom left.

In past years, North Korean soldiers have dug tunnels under the DMZ (some discovered in 1974, '75, '78, and '90) and the forces on both sides have erected tank barriers, minefields, electric fences, sentry posts, ramparts, perhaps even concrete walls. But by and large, no one lives there, no one disturbs the native wildlife, and no one for the foreseeable future plans to come in.

Other than one tiny South Korean village with some 200 rice farmers near the western end of the DMZ, no humans are allowed to reside within the area. Limited rail links have been built in recent years, mostly to promote South Korean tourism to the North, but are often unused. Besides patrols on the respective sides of the DMZ, this has become a piece of the planet untouched by man.

The DMZ's bisection of the Peninsula also means it traverses numerous unique biospheres, capturing mountains, prairies, swamps, rivers, lakes, and marshes within its limits.

Almost 3,000 different species of plants, 70 different mammals, and 320 different kinds of birds inhabit the area. Among them are some animals sacred to regional religions, which had lost long ago their other traditional habitats. Red-crowned cranes, revered in Japan as a symbol of longevity and in China by Taoists as a representation of immortality, now find a refuge only a few miles away from menacing North Korean artillery tubes. Asiatic black bears, long hunted throughout the continent from Pakistan to Eastern Russia, now subjected to inhumane exploitation for their bile -- used in traditional medicines -- can also be found within the DMZ.

That has already prompted some, like CNN media mogul Ted Turner, to extend a verbal offer of monetary support to turn the DMZ into a reserve park and world heritage site, first made in 2005. A good idea for some yet unseen point into the future, when a national park one-quarter the size of Yellowstone may be allowed to welcome visitors from both North and South.

But in the meantime, other, far more rare species are thought to be moving in.

Large predators have mostly disappeared from East Asia, their home ranges disturbed by human development or their traditional food sources diminished from expanding human settlement. The near-extinct Amur Leopard, of which only less than two dozen adults are believed to still be alive, is thought by conservationists to have made a home in the region.

A unified Korean Peninsula, as a tiger. Photo from Big Think's Strange Maps blog.

Even more spectacularly, South Korean wildlife experts think about ten Siberian tigers, all but wiped out from the Peninsula, may now reside within their section of the DMZ. Optimistic because of markings, scratches, tracks, and devoured animal remains, they think the animals may now have a chance to establish a home in the area. Some are even pushing for areas of the DMZ to be opened to allow the ghostlike South Korean tigers to cross over to breed with counterparts in the North. No one is really sure how many tigers are in North Korea, since no real surveys have ever been carried out in the reclusive nation in recent memory.

If that were to actually happen, environmentalists would not be the only ones to take away deep meaning from the occasion. The image of the tiger has often been used to represent of a united Korea.

Yet, so far, scientists and conservationists working in the field have yet to produce any hard evidence of the existence of the big cats, despite deploying a large array of cameras and sensors. Meaning that, for the time being, the real tigers may be as elusive as the idyllic political condition they symbolize.