I'm planning on tearing out my sidewalk that I assume is 40-50 years old or so, maybe older. The place where it is was probably used as a walking path before the cement was poured. My house was built about 1900 and my small town of Trenton, MO was first settled in 1834. I don't know if my house lot was lived on before 1900 though, it most likely was. I've never detected under a removed sidewalk before and can only imagine it would be really promising. It would be a concentrated area where coins and items would have been dropped/lost before the sidewalk was poured. Has anyone else here detected under sidewalks? Do coins continue to sink under sidewalks even though its protected from rain and cracking from dry weather? I would think everything under a sidewalk would stay just as it was when it was poured and not sink at all. That would save about 50 years or so of sinkage. After I'm satisfied that I found all the signals, I may even remove 5 inches or so and go over it again. I'm always shocked when I find an early 1800's coin assuming it should be very deep by now. Some people talk about digging wheat cents at 12" or more and they can only be about 100 years old at most and likely dropped much more recently than that.