Treasure hunters using electromagnetic pulse measurements to search underground near the German-Czech border have found a manmade cavern that they believe contains the Amber Room, an 18th century Russian palace chamber stolen by Nazis during World War II, reports Spiegel Online via Bloomberg.

"I'm well over 90 percent sure we have found the Amber Room," said Heinz-Peter Haustein, mayor of the nearby village Deuschneudorf, who led the search. "The chamber is likely to be part of a labyrinth of storage rooms that the Nazis built here. I knew it was in this area. I just never knew exactly where."

The room, made of panels covered with amber, gold leaf, and a fossil resin, was given to Czar Peter the Great by Prussian King Wilhelm I in 1716, according to Spiegel. In 1941 Nazis dismantled and removed it from the Catherine Palace near St. Petersburg (then Leningrad) and shipped it to Konigsberg (then Kaliningrad). It hasn't been seen since 1945.