Completed by the Nazis in 1938, the Eagle's Nest escaped destruction after their defeat in 1945.

Since then, it has become a popular tourist destination and houses a mountain inn.

It serves as "a cautionary reminder of the abysses of the inhumane Nazi dictatorship", according to its official website, external.

During WW2, Hitler and his followers were responsible for the deaths of tens of millions of people, including the mass murder of European Jews. Homosexuals, gypsies, the disabled and ethnic minorities were sent to concentration camps and put to death.

There has been a wider debate in Germany and Vienna over whether to preserve, repurpose or demolish buildings connected to Hitler.

While some say these buildings should be preserved for historical reasons, others have raised concerns that they could be used as monuments or places of pilgrimage for neo-Nazis and far-right extremists.

In June, Berlin authorities announced they would tear down one of Hitler's bunkers - described at the time as "the power centre of Nazi Germany" - to build flats and offices on the site.

Those critical of the plans said the bunker had "significant historical value" and that it should have been turned into a museum and memorial site with an exhibit about the end of the war.

And in July, after years of controversy, Austrian authorities refurbished the house in the town of Braunau am Inn in which Hitler was born and turned it into a police station.