In 1970, when the Osaka Expo'70 took place, Mainichi Newspapers and Matsushita Electric Industrial Co. built two 1-meter diameter, 2 tons capsules, made from a special metal alloy.
Hoping for never ending world peace and prosperity, these capsules were filled with 2098 cultural assets of the 20th century and were buried 15 meters deep right under the monument from this picture (the metallic dome in front of the castle).
The first capsule will be opened at the beginning of each century, it was already opened in 2000 and the next opening will be in 2100. Tree seeds from this first capsule were retrieved and three Japanese red pine seeds have been grown and transplanted in Suita, the site of the Expo'70.
But you wouldn't believe the destination of the second capsule... it will be opened after no less than 5000 years, in 6970!
EXIF info:
Nikon D90
Lens: VR 18-55mm F/3.5-5.6G
Focal Length: 55mm
Aperture: F/5.6
Shutter Speed: 1/640s
ISO Sensitivity: ISO 200