Short answers, pulled from the story.
Hitler moved into the Führerbunker on the 16th of January 1945. He remained there until his death on the 30th of April 1945, making it the seat of the Nazi regime in the final months of World War II in Europe.
The Führerbunker was located approximately 8.5 metres beneath the garden of the old Reich Chancellery in Berlin. Its roof was made of concrete nearly 3 metres thick, and approximately 4 metres of concrete protected its roughly thirty small rooms.
Eva Braun married Hitler in the Führerbunker just after midnight between the 28th and the 29th of April 1945, in a small civil ceremony. Less than 40 hours later, both died by suicide inside the bunker.
The above-ground Chancellery buildings were levelled by the Soviets between 1945 and 1949. The underground complex largely survived until 1988-89, when construction work uncovered and mostly destroyed the excavated sections. Some sealed corridors still exist beneath a car park in central Berlin.
A single information board was installed at the corner of In den Ministergärten and Gertrud-Kolmar-Straße on the 8th of June 2006, about three minutes' walk from Potsdamer Platz. The board contains a schematic diagram and was designed as a historical record rather than a memorial. The remaining corridors are sealed off from the public.
The construction cost for the Führerbunker totaled 1,349,899.29 Reichsmarks. It was built by the Hochtief company as part of an extensive programme of subterranean construction in Berlin begun in 1940, with the lower Führerbunker section completed in 1944.