"There was a little working room, a living room, bedroom, toilet and shower and there was no more," said the last surviving witness to the final two weeks of Adolf Hitler's life, referring to the Nazi leader's underground quarters.
Gazing at the carpark which now covers the bunker, Misch recalled his time as a member of the Fuehrer's close entourage in the days leading up to April 30, 1945.
The 88-year-old, who still lives in Berlin, served Hitler throughout World War Two as a bodyguard and telephonist.
But as the Third Reich came to an end, Hitler withdrew to the underground shelter beneath his chancellery and dismissed most of his staff, retaining only those whose services were considered essential - including Misch.
"We were expecting it. Hitler let us go on April 22. I was here in Berlin ... and we stuck it out until April 30," he said.
Misch's account of Hitler's last days is worn smooth from years of retelling. His answers to questions sometimes run off at a tangent but his feelings - particularly about the subsequent portrayal of the events of that spring - are clear.
"Hitler was not, as the press writes, from February on down here vegetating," he says. "He always came out and went up to his apartment in the flat and I went to my room.
"He came down when there was an air raid warning and so I came down too."
Hitler's bride, Eva Braun, whom he married two days before their deaths, also moved into the bunker, Misch says. "(In the last few weeks) Eva came and then they stayed down there for the last 12 days."
"Herr Misch is the last one still living who spent the last 15 days in the bunker and experienced the end," said historian Dietmar Arnold, head of the Berlin Underworlds organisation which was responsible for the sign.
The bunker was filled with gravel and covered by a carpark in the 1980s by the East German government. There is no trace of it left, nor of Albert Speer's monumental New Reichs Chancellery that once stood nearby.
Misch welcomed the sign - hoping it would help bring him respite from the hundreds of journalists, historians and archivists who want to tap his memories of the man behind the Holocaust.
"Groups come here every day, they want to know; then they come to me, then they want me to come here. "They want explanations. It can't go on," he said, his voice trailing off before he launched into another reminiscence.
"There were two witnesses. We were the observers who heard and saw everything that went on down there," he said.
Misch and mechanic Johannes Hentschel were two of the last people remaining in the bunker as Soviet troops advanced on Berlin. Misch was later captured by the Russians and interned. He was released in 1954 and returned to Germany.
However, he remains a controversial figure in Germany for his dogged faithfulness to the memory of a man who was responsible for the deaths and persecution of millions. Misch, who witnessed so much, is still haunted by images from the past: like the deaths of Nazi propaganda minister Joseph Goebbels' six children.
"The Goebbels children were made ready to die in my room. I know all about (it). Frau (Magda) Goebbels could not prepare them where they were sleeping, there were still staff there.... So she came down to the bunker - nobody came there - and she prepared the children for their deaths in peace. That happened in my room."
Misch faced fierce criticism in calling for a plaque to commemorate the children - Helga, Hilde, Helmut, Hedda, Holde and Heide - and still seems upset by the memory of the days leading up to the childrens' deaths by poisoning.
"It was such a drama, there were tears, you can't imagine," he said.
While the details of Hitler's suicide are well-known, Misch's account is still chilling. By April 22, 1945, an intercepted message from the Western allies convinced Hitler than the end was near.
He sought advice on how best to commit suicide, fearful of falling into the Russians' hands as they descended on Berlin. His German shepherd Blondi was sacrificed in order to test whether cyanide capsules Hitler planned to use were genuine. "On April 22, he definitively declared an end: 'The war is lost. You can all rely on me, I will never leave Berlin'," Misch recalled.