The biggest hoard of Nazi treasure was found in the tunnels below the city of Merkers in Germany.
The Nazi treasure of Merkers Mine was only discovered when the U.S. Army marched into the German town of Merkers-Kieselbach towards the end of World War II. The army received a tip-off from two women that there was an abandoned salt mine near Merkers that was used as a storage for gold and other loot that the Nazis had recovered from their conquests.
When the Americans entered the mine, they had to descend 2100 feet below the surface to discover the haul. The treasure was kept in a vault with walls that were three feet thick. The vault was 75 feet wide, 150 feet long, and had a 12-foot high ceiling.
Inside the vault, there were thousands of bags, boxes, suitcases, and trunks holding gold bars, gold coins, gold bullions, silver, and platinum. There was also foreign currency including American, British, and French currencies as well as the German Reichsmarks. In addition, there were 400 tons of stolen artworks. The total value of the looted treasure was estimated to be more than $500 million (or $8 billion in today's value).
The treasure was even inspected by General Dwight D. Eisenhower who was reported to be in awe of all the gold in the vault.
Eventually, the treasure was moved and some of it was given back to the central banks of Europe and also used for restitution to individuals who were persecuted by the Nazis.