metal disc, have 3 of them and i will be placing them in stages as i fill in the soil, hope its sets of detectors!!! find one and keep digging, abit more soil then the next the last one goes about 5 odd inches from the surfaceIs that a coin or just a metal disc? Something to react strongly to a Metal detector would be good left in the hole.
Good idea might just do thatTo increase the chances of it being found you could create some “treasure maps”and stash them im weird places like under floorboards or in disused flues. Messages in bottles.