YANGGU, South Korea — Within earshot of a truckload of South Korean troops, a family of wild boars approaches a military base looking for an afternoon snack. Just down the road, water deer dash into a forest dotted with mines.
The Demilitarized Zone separating about 2 million soldiers of the two Koreas is the world's most heavily fortified border and has been off-limits to most civilians for more than 50 years.
And that has made it an unlikely haven -- though not an entirely safe one -- for wildlife.
"It's easy to see wildcats and boars around here. Sometimes I see badgers, weasels and elk," said South Korean Sgt. Lee Jae-ho, whose 21st Infantry Division patrols the zone. "But with the minefields, I also see some animals with broken legs and other wounds."
After the Korean War ended in 1953, the 150-mile long, 2.5-mile-wide strip and adjacent civilian-controlled zones to the south were created, displacing farms and villages.
The area is now a virtual no man's land of mines, sandbagged bunkers and guard posts. The Civilian Controlled Zone or CCZ is surrounded by a barbed wire fence whereas the DMZ is marked by a heavily guarded 13-foot-high wall.
Encompassing soaring mountains, rolling lowlands and coastal wetlands, the zone also is one of the most biologically rich on the Korean Peninsula, scientists say.
Hundreds of bird species winter here, among them at least two endangered types of crane -- white-naped and the red-crowned, or Japanese. Fifty types of mammals live here, including the rare Asiatic black bear, Amur leopard and, some believe, the Siberian tiger, based on traces of footprints and droppings. More than 1,000 different plant species thrive in the area.
With increased development around the border and hopes of a North-South reconciliation, conservationists are stepping up calls to have the zone proclaimed a nature reserve.
"Many of the species you find in the DMZ or the CCZ are no longer found in the rest of the country," said Ke Chung Kim, a Penn State University professor and chairman of the nonprofit DMZ Forum.
"We should have the North and South Korean governments preserve this area for long-term conservation," he said. "Unless that is done, the DMZ may not last as it is now. That is my serious concern."
Conservationists worry that peace will bring back farming and population, and that if North Korea's economy collapses, refugees would flood the zone.
"The demand for development of this area is already high and we have to consider the people who have rights to the property here," said Chung Ok-sik, a Seoul University graduate student researching birds in the area.
A few key sites, such as the wetlands of Cheolwon basin, where the cranes spend winter, should be protected, he said.
The conservationists' efforts got a boost in November when CNN founder Ted Turner visited the two Koreas and said the DMZ should become a peace park and World Heritage Site to honor soldiers killed in the Korean War.
The United Nations body that designates heritage sites supports the idea, and South Korea's environmental ministry has asked North Korea to join it in jointly nominating the DMZ, said Son Woo-rak, a ministry official. North Korea hasn't responded yet, Son said.
Meanwhile, there are slight signs of a thawing in relations between the two nations. Rail and road links to North Korea are being reconnected through the DMZ and the heavily guarded border area gets a steady influx of tourists.
Seoul-based Hyundai Asan Corp. in 2004 opened an industrial complex in North Korea near the DMZ, bringing together northern labor and South Korean management. It also runs a resort in North Korea, Mt. Kumgang, or Diamond Mountain, that attracts hundreds of thousands of South Korean tourists annually.
The South Korean government has built bridges and tunnels over and under the roads in the DMZ to protect wildlife.
Inside the civilian zone near Yanggu, about 50 miles northeast of Seoul, the military presence is intertwined with nature. The sounds of Korean magpies and yellow-throated bunting compete with the buzzing of a chain saw at a military base. Signs posted outside the thick forest warn of mines, and a picturesque valley houses a shooting range with cutouts of North Korean soldiers.
Looking out over rolling hills that give way to rugged mountains blanketed with pine trees and Mongolian oaks, Chung says the landscape harks back to a simpler time before skyscrapers, golf courses and strip malls came to South Korea.
Here, "nature remains raw," he said. "This could serve as a model of how you take an area once inhabited and return it to nature."
Associated Press reporter Yu-sup Lee in Seoul contributed to this report.