time capsule

Time capsule plaque in Ypsilanti, Michigan, with instructions for the capsule to be recovered and opened upon the city's bicentennial, on July 4, 2023 Typewritten documents recovered in 2021 from a capsule buried in the 1940s

A time capsule is a historic cache of goods or information, usually intended as a deliberate method of communication with future people, and to help future archaeologists, anthropologists, or historians. The preservation of holy relics dates back for millennia, but the practice of preparing and preserving a collection of everyday artifacts and messages to the future appears to be a more recent practice. Time capsules are sometimes created and buried during celebrations such as world's fairs or cornerstone layings for buildings or at other ceremonies.