Adolf Hitler's secret fortress 'Wolf Lair', located deep in the heart of a forest in north-eastern Poland, is to be turned into a major tourist attraction.
Forestry workers are looking for an investor to help make the Nazi leader's ruined fortress more accessible to holidaymakers, the Daily Mail reported.
The camouflaged complex in the woodlands of what was once German East Prussia was one of Hitler's key military headquarters during World War II.
It was built in 1940 and 1941 to protect Hitler and other top Nazi officials from air bombardment during Operation Barbarossa, the invasion of the Soviet Union.
The Wolf's Lair is popularly known as the site of a dramatic assassination attempt on the dictator by Colonel Claus von Stauffenberg in 1944.
The Nazi forces destroyed it as they retreated in early 1945.
The hideout - whose name references Hitler's nickname, 'Mr Wolf' - consisted of 80 buildings at its peak and is now owned by the local forestry authority.
The spot is open to the public, but does not attract many visitors because it is tucked so far into the forest and accessible only by treacherous dirt roads.
Staff said they had begun looking for investors to help build a museum and put the lair on the map for tourists.
"We are waiting for offers," said local forestry official Zenon Piotrowicz.
"The requirements are quite high because we want a new leaseholder to invest a lot, particularly in a museum with an exhibition that could be open all year long," Piotrowicz added.
The fortress near the Russian border had its own power plant and a railway station.
The complex was heavily camouflaged and surrounded by a minefield, which took 10 years to clear after the war.