Marbles are buried in every yard that had children and will not be rare to future civilizations. They were very popular. Keys are the second most found item bur

Marbles are buried in every yard that had children and will not be rare to future civilizations. They were very popular. Keys are the second most found item buried in yards. This was a recent discussion in r/gardening. I can attest to this as I've torn out an entire front lawn and topsoil from a 1964 tract home, sifted every square inch of it through 1/4" hardware cloth to build raise beds for vegetables. The findings were, in order, so many marbles, over half dozen keys, little plastic dinosaurs or other toys, two 9mm slugs (likely from people shooting up into the air as they were not deformed.)