Topic summary
Time capsules
Extracted from the Wikipedia article Time capsule.
Personal and domestic time capsules
Commercially manufactured sealable containers are sold for the protection of personal time capsules; some of the more durable waterproof containers used for geocaching may also be suitable. Many underground time capsules are destroyed by groundwater infiltration after short periods of time; caches stored within the wall cavities of buildings can survive as long as the building is used and maintained.