A fire broke out at the Kehlsteinhaus retreat, more commonly known as Adolf Hitler's Eagle's Nest, on Friday evening, Bavarian police said.
The Kehlsteinhaus was engulfed in flames, a police statement read, adding that a suspect has been arrested and the incident was being criminally investigated.
What do we know so far about the Kehlsteinhaus fire?
A fire alarm went off at the Kehlsteinhaus on the Obersalzberg in Berchtesgaden at around 9:15 p.m. local time (1915 GMT) on Friday, the police said in a statement.
"The fire brigades, who were alerted immediately, could already see flames clearly visible at the Kehlsteinhaus as they approached," the police statement read.
Firefighters struggled to reach the Kehlsteinhaus, which sits at some 1,834 meters (6,017 feet) above sea level, with their engines.
Police added that the building and its immediate vicinity could only be entered while wearing respiratory protective equipment (RPE).
Police said they were unaware of any injuries as of yet.
The site once housed Hitler's heavily fortified country residence, where he is believed to have partially written his book "Mein Kampf."
It remains a symbol of the Nazi regime and is among only a few monuments of the Hitler era that survived the World War II bombing unscathed. Today, it is home to a popular restaurant.
