We’ve all seen retirees and hobbyists sweeping beaches with metal detectors, but German hobby-historian Peter Lohr has taken it to another level.

Lohr, like many others, has been fascinated with the Jonas Valley in Northern Germany for years. Toward the end of World War II, Nazi officials used prisoners from the Buchenwald concentration camp to dig a network of 25 tunnels deep under the valley, intended for use in secret Nazi projects. “Secret Nazi projects” gives conspiracy theorists, hobby historians, and people with active imaginations license to assume that any manner of crazy shit might be hidden in the tunnels, but Lohr wins the prize for the most distressing claim to date.

Using a special ground-penetrating radar system, connected to a 3D-imaging display, Lohr claims to have discovered several large caverns deep underground, with five mysterious metal objects hidden inside. Of the five, Lohr says two are nuclear bombs, relics of Hitler’s last-ditch efforts to develop a super weapon that have been rusting quietly underground for over 70 years.

“The metal’s been lying there for 71 years,” Lohr told the German local paper Bild. “At some point it will decay and then we will have a second Chernobyl on our hands.”

The Nazis were pursuing a nuclear weapons program officially until 1943, when it was scrapped, but historians and conspiracy theorists have long speculated that Hitler’s lost nukes were still out there.

Lohr’s primary device was a Ground Penetrating Radar (GPR) unit, which is available to hobbyists and researchers alike for prices between $4,000 and $7,000. The GPR sends out radar pulses, similar to those used to detect ships and airplanes, deep into the ground. When they hit an object with a different “permittivity,” or receptiveness to electromagnetic forces, they break up and bounce back to the surface.

Lohr connected his GPR to a 3D imaging display, which he claims let him accurately identify the metal objects hidden deep underground.

This GPR unit is being used to search for artifacts in Central Park, but it's probably similar to Lohr's. 

The Independent reports that German authorities have put the brakes on Lohr’s research, telling him he cannot continue to map out the alleged bombs. While his assertions are pretty freaky — rusty nukes buried in a German valley is enough to make anyone nervous — it’s worth noting that this is far from the first time hobby historians have claimed to find some crazy shit that the Nazis buried.

A Project Riese area built by the Nazis.

Back in November, treasure hunters claimed to have found a train full of Nazi gold buried under Poland, and the Jonas Valley was the subject of a recent exhaustive New Yorker piece about the secrets of the mysterious tunnels.

In the case of the train, expert researchers eventually stepped in and called bullshit — they found no evidence of a Nazi treasure-train, despite the amateur’s claims. Lohr has just gone public with his claims, and while his GPR-3D imaging setup looks pretty sophisticated, declaring a possible “second Chernobyl” is a pretty big stretch. It’ll probably come down to professional researchers to figure out what the looming metal things under the Jonas Valley are.

The Jonas Valley