In Bulgaria, the Ministry of Defense is preparing to auction off a piece of European military history, which has been lying forgotten and half-buried in the ground for decades.
Collectors of vintage military vehicles are already lining up to bid on some of the more than 40 Nazi German tanks, which were once used to protect Bulgaria's southern border during the Cold War.
In the rolling farmland of Bulgaria's southern border with Turkey, 60-year-old Piotr Dmitrov herds a flock of sheep past a hilltop where a half-dozen rusting tank cannons poke out from between the weeds.
"The tanks have been there since I was a child," Dmitrov says. "The government used to make us practice shooting the guns, in case the Turks invaded.
Dmitrov says the tanks have been there since he was a child and that they're from the Germans. He says the government used to make them practice shooting the guns, in case the Turks invaded.
In the dark days of the Cold War, communist Bulgaria fortified this border with Turkey, which was a member of the rival NATO alliance, by embedding scores of Soviet and Nazi tanks in a network of concrete bunkers.
The bunkers have been abandoned for years.
Concrete steps into the bunker are littered with twigs and old leaves. A shaft of light streams down from the turret of a tank gun that was half buried in the ground — its cannon facing toward Turkey.
In 2004, Bulgaria joined NATO. The old German panzers were left rusting and all but forgotten. Many of them fell prey to scrap metal hunters, who, in many cases, have left little but the chassis of a tank intact. But in the turret of one Panzer IV, you can still see the German label "Leuchtpistole," amid peeling paint and rust.
This month, the Bulgarian government suddenly announced it was unearthing the vehicles and selling them in an auction.
"We see much more interest in the tanks today after one of the most valuable vehicles was stolen. This tank had an inscription, proving it was a gift from Adolph Hitler to the queen of Bulgaria," says Blagoy Milenov, deputy director of Bulgaria's National Museum of Military History.
Milenov says Hitler's tank mysteriously disappeared sometime last fall.
In December, Bulgarian authorities arrested two German citizens and a Bulgarian army officer and accused them of stealing the tank and somehow smuggling it out of the country.
"No, they have no proof, nothing," says Thomas Gmeiner, one of the German defendants in the case. He runs a private tank museum in Germany, which has a collection of more than 60 tanks, mostly from WWII.
Gmeiner denies stealing the tank. Released on bail, he fought the charges against him for two months in Bulgaria. In February, however, Gmeiner abruptly fled the country.
Speaking via telephone from Germany, he says he is a wanted man in Bulgaria.
"Yes, it's very funny," he says, laughing, before explaining in broken English: "I see there is not any chance to come home soon. I have a business to run. I have a family and a home. And then I escape."
This week, the Bulgarian government was supposed to hold an auction for some of the remaining Nazi tanks. But at the last minute, the auction was postponed.
Milenov says the Bulgarians realized the starting prices of the vehicles were far too low.
"Collectors are prepared to pay inappropriately large amounts of money for these valuable pieces of military heritage," says Milenov.
Milenov calls the tanks a historical gold mine, but for some Bulgarians, they were more of a playground.
At a sheep farm near the border, 25-year-old Ivan Zheliaskov says he grew up playing on the tanks near his childhood home.
"For me, this is normal — when I see the tank," he says.
Zheliaskov is now a border guard who protects the Bulgarian frontier from what he says is a very different threat from the one his predecessors faced. Migration experts say thousands of economic migrants from the Middle East and Africa try to smuggle themselves illegally into Bulgaria each year, in a desperate and dangerous quest to enter the much wealthier European Union.
"Dangerous is the people from Iraq, from Iran [who] want [to come] here. Want to come many people. This is the problem," he says.
Illegal immigration is a 21st century challenge for Bulgaria that even modern-day tanks cannot solve.