The answer may be Karlsruhe.

A German ship sunk by Soviet warplanes in 1945.

"We have been looking for the wreck since last year, when we understood that one of the most interesting stories may be hidden on the seabed of the Baltic Sea," Polish diver Tomasz Stachura said in a statement quoted by Reuters.

The so-called amber room was donated by the then Prussia to Tsar Peter the Great in 1716. The magnificent hall from the castle in Berlin was rebuilt in the Catherine's Palace near St. Petersburg in Russia as part of the then war diplomacy in a ravaged Europe.

The horrors of war

But it also came to symbolize the horrors of World War II.

The entire hall outside what was then Leningrad was to be moved by Soviet soldiers, who failed, and instead the walls were covered with cheap wallpaper to deceive Nazi soldiers.

During the Nazi invasion, the room was found, dismantled and taken as booty to the then Königsberg in East Prussia, on the shores of the Baltic Sea.

Then the war turned;

In one of the largest sea evacuations in history - Operation Hannibal - about one million Nazi soldiers and civilians were evacuated from the city of Königsberg.

The British Air Force RAF had then bombed the city, and the Soviet army had launched the ground offensive operation Samland with Königsberg as a target in March 1945.

Then the last traces of the amber room disappeared.

Six tons of amber disappeared

The war-torn Königsberg became Kaliningrad in the Soviet Union, an enclave sandwiched between present-day Poland and Lithuania.

The castle was demolished by order of Soviet leader Leonid Brezhnev in 1968, despite protests.

And no traces were found of the hall.

The theories, the hunt and the search for about six tons of amber, quite a lot of gold and other things, continue unabated.

And now the diving team from the group Baltitech hopes to find the treasure.

The ship Karlsruhe, heavily loaded and with 1,083 people on board, hurriedly left Königsberg in the raging final battles of the war.

It was sunk by Soviet warplanes off the coast of Poland.

"The wreck is almost intact.

We have found military vehicles, porcelain and many boxes whose contents are still unknown, "says Stachura.

While the search continues, there is a fairly accurate copy of the room rebuilt in the Catherine's Palace in present-day St. Petersburg.