There’s an air of mystery to the Owl Mountains of southwestern Poland. The ancient range is thick with spruce and dotted with medieval towns. It’s home to a centuries-old castle built by a man known as “the Raw” and occupied by Hitler himself. And several meters beneath the mountains’ broad peaks lies a network of crumbling, unfinished tunnels, dug by slave laborers for some unknown purpose and then largely abandoned at the end of World War II.

In other words, this is the exactly the kind of spot the Nazis might have stashed a train full of stolen treasure. If such a train existed.

There’s reason to believe it might — or more reason than usual, at any rate. After two anonymous treasure hunters announced last week that they’d located the legendary loot, Marika Tokarska, an official in the nearby city of Walbrzych, told the Associated Press that authorities “believe that a train has been found.”

On Thursday, Polish culture ministry official Piotr Zuchowski issued a statement urging treasure enthusiasts not to go hunting for the train — which he said he is “certain” is real — on their own.

“There’s a huge probability that the train is booby-trapped,” he said, according to the BBC.

This is not the first time Polish authorities have lent credence to rumors of hidden treasure in the area. Officials quietly excavated parts of the tunnel system in the 1960s, but turned up nothing more than a few old coins. According to the BBC, they looked again in the 1990, without any luck.

“We have had a lot of stories like that in the last few years with people claiming they know where the train is,” Joanna Lamparska, a Polish author who has written about the train, told the AP. “But nothing was ever found.”

But that is unlikely to dampen the excitement in Walbrzych, where rumors about the supposed “gold train” have long been endemic and traces of the Nazi presence still linger.

The Germans arrived in 1939, during the swift invasion of Poland that touched off the start of World War II. The noble family that lived in the local castle, Ksiaz, fled the country — one of the sons changed his name and joined the British air force, another fought in the Polish army. Two years later, the Nazis seized the castle, according to the Ksiaz Web site.

Eduard Wawrzyczko, who had worked as caretaker at Ksiaz for 49 years by the time the Germans arrived, watched in mute horror as the sumptuous 200-room residence was turned into military barracks.

“In 1943, Hitler came here with [Nazi official Hermann] Goering and they went through the castle,” he told the New York Times in 1961. A Times reporter had been sent to the rural corner of Poland after a hullaballo arose about secret Polish military excavations of the tunnels.

“They they pillagers came and they turned Ksiaz into this,” Wawrzyczko said.

“This” was a bare, crumbling ruin, gutted of its Baroque finery. Goering was one of the chief orchestrators of the Nazis’ art confiscation program, and he quickly stripped Ksiaz of its valuable art and furniture. After everything of value was carted away, the castle was turned into housing for soldiers. The 300-year-old ceiling frescoes were obscured with a thick layer of whitewash and the elaborate mosaics ripped from the tile floors.

Not long after that, the Germans started work on their mysterious tunnels, Wawrzyczko told the Times.

“They brought in the Todt organization for that, with slave labor,” he said, referring to the Nazi engineering arm notorious for its use of forced labor.

The tunnel project was dubbed “Riese,” meaning “giant,” according to the AP, and it’s still not clear what it was for. Many believed that Hitler intended to make the Riese complex into his new headquarters. Others speculated that weapons would be stored in the subterranean caverns, or that a secret rail system was being built underground.

On the corners of the Internet inclined toward conspiracy, theories circulate that “Die Glocke” — a purported Nazi superweapon that has so far only been found in the pages of science fiction novels — might be hidden somewhere beneath those ancient mountains.

It is known that concentration camp inmates and prisoners of war were brought to the site to build the tunnels. Thousands of them are said to have died while working underground, killed by illness or falling rock or the sheer deprivation that was common in Nazi work camps.

According to a guide to the Riese complex published by the Krzyzowa Foundation for Mutual Understanding in Europe, which is based in southwestern Poland, German sources from the period suggest that the Nazis aimed to build a vast underground shelter encompassing at least 10 square miles.

“On entering the tunnels, the true scope of this wholly unrealistic construction project becomes obvious,” the guide’s author writes. “It is only one example of Nazi megalomania.”

The complex was abandoned in 1945, when the Soviet Army took control of the area. Only about five miles of tunnel had been blasted into the rock before the Germans left, much of it rough hewn and structurally unsound.

But rumors about the project lingered. Chief among them is a legend about an armored train that had departed the city of from Breslau (today the Polish city of Wroclaw) in the waning days of the war and headed toward what is now Walbrzych, 40 miles away.

According to Smithsonian Magazine, the rumor about the train “essentially comes from a game of telephone.” Some German miners allegedly told a Polish miner that they had seen a train being wheeled into a tunnel beneath the Owl Mountains. The train is believed to have been carrying fabulous treasure — gold, jewelry and possibly weapons confiscated from Polish citizens — further into Nazi territory, where it could be hidden away.

It was a common tactic for Hitler’s retreating army. Beginning in late 1944, as the Allied bombing of Berlin intensified, the Reichsbank began shipping its reserves of gold and other confiscated treasures around the country for safekeeping. Old mines were prized hiding spots, according to a 1999 article in National Archives’ magazine “Prologue,” because they were sheltered from bombs.

In April 1945, a month before the end of the war in Europe, American soldiers took control of the town of Merkers in central Germany. They would have pressed on, but a French prisoner who had been working in a local salt mine whispered to one of the Americans that the Nazis had been hiding gold there. Pressed by American officials, the mine’s operators confirmed the rumor. Three days later, a battalion headed into the underground tunnels, unsure of what they would find.

Their inventory list reads like the contents of a mythical hoarder’s cave: 8,198 bars of gold bullion, 63 boxes and 55 bags of silver plate, 1 bag containing six platinum bars, crates filled with valuable artwork, gold and silver wristwatches, forks, spoons cigarette cases, jewelry, false teeth. Most of it had been confiscated from concentration camp prisoners. Little of it would find its way back to them.

A “Hungarian gold train” carrying loot stolen from Jewish concentration camp prisoners was similarly sent from Budapest in 1944. It meandered its way through Hungary and Austria, occasionally stopping to load some of its contents onto trucks, and was seized by American forces the following spring. At that point, much of the trains contents had been scattered throughout the region — their whereabouts are still a mystery. Much of what remained was auctioned off by the U.S. Almost none of the valuables were returned to their original owners.

No one knows what the purported Polish gold train might contain, if it even exists. Whatever it is, the two alleged discoverers — one German, one Polish, both of whom wish to remain anonymous — want 10 percent of its value in exchange for revealing its location, according to the AP. They’ve hired a lawyer and submitted documents to Polish authorities, who say they’re willing to pay the reward if the information pans out.

If it doesn’t, it wouldn’t be the first time. Wawrzyczko, the Ksaiz Castle caretaker who spoke to the New York Times when they investigated a gold train rumor in 1961, said he was positive there was nothing to find there.

“They took away the pictures and everything long before the tunnels were dug,” he said. “There is nothing left here.”