The capsule, a large black cylinder, was found buried beneath a center for education and training of Nazi workers and officers and was apparently buried on April 22, 1934.
Researchers opened the capsule and discovered a trove of pictures, newspapers and documents from Nazi Germany along with two copies of Mein Kampf, which outlined Hitler's views on racial theory and delineated his radical ideology. Also contained within the capsule was a letter written to the future residents who would later discover it.
The existence of the time capsule was known to researchers, but for decades they were unable to access it due to the complex excavation process involved which included penetrating thick layers concrete and dodging mines planted by the Nazis. Researchers say the items were preserved in excellent condition.