time capsule 
noun
A container storing a selection of objects chosen as being typical of the present time, buried for discovery in the future: the opening of a time capsule dating from 1904 the house had stopped in time, like a time capsule...
- On Monday, they'll bury a time capsule containing work from every child in the school - to be reopened in 2013.
- Very soon, a vast time capsule will be buried containing all manner of goods and items intended to wholly embody 20th century life.
- A window to the past was opened by pupils at a Yorkshire school yesterday, after the discovery of a time capsule dating back to 1891.
- grimness
- grimoire
- Grimond, Jo
- Grimsby
- grimy
- grin
- grin and bear it
- Grinch
- grind
- grind away
- grindcore
- grinder
- grind house
- grinding
- grindingly
- grinding wheel
- grind on
- grind someone down
- grind something out
- grindstone
- grind to a halt (or come to a grinding halt)
- gringo
- grin like a Cheshire cat
- grinner
- grinningly