I don't know if this counts but I will post it anyways!
In 1983, I was metal detecting around an old Fort in Key West that was used during the Civil War for target practice, was and (I believe) still is a State Park but has been granted use by the Key West Garden Club. After getting bored from finding hundreds or more flip-tabs, I asked the Security Guard if I could metal detect inside the Fort. I was advised no but I could metal detect the arched entranceway. However, I could not keep anything I found. I did not get a single metal target inside the entranceway but did find that there was a void about 6 feet long and about 4 1/2 to 5 feet wide in the center of the entranceway. This was evident on my' old White's 2000-D Series 1 Metal Detector by the slight signal that I had in my' ear, completely went blank right after a "Vooop" sound made by the metal detector. I had encountered this before and knew what it was which is very similar to when the coil crosses a large piece of completely degraded Iron. I asked the Security Guard if I could dig down in the entranceway to find out what if anything was there. After consulting with the person in charge, he advised that I could not. I then advised him that there is possibly a room, cavern or tunnel underneath the entranceway that should be investigated. About 4 months passed and I ran into the Security Guard and he told me that after 3 months, they had gotten permission from the State to excavate the floor of the entranceway. During the excavation, he stated that they found that the void was an entrance to a room under the Fort which contained 3 cases of (what he believed were) brand new Brown Bess Rifles still packed in packing grease, barrels of gun powder, bullets and other related items. I never got to see any of the rifles or other items, was never even thanked for making the initial discovery and never found out what the rifles and other items were worth. The Security Guard stated that rifles and other items were quickly wisked away under darkness to an unknown location. To this day, I have never heard anymore about them and the find was apparently kept secret between a select few with the exception of (I believe) 3 Brown Bess Rifles were supposedly donated to the State Museum.
Frank
Note: For everyone's information! If you have an older White's or possibly other brand of old metal detector and you have an audible signal in your' ear but the signal goes "Vooop" then disappears completely, this could be a void, cavern or tunnel underneath you or could be a large piece of degraded Iron. It could be a clue to a significant find or not but just don't discount it as nothing until you investigate. You can somewhat map how large the void is by marking where it starts (i.e. the signal goes "Vooop" and signal drops out completely) and marking where the signal comes back. If done correctly, you can get the width and length of the void! It would behove anyone that excavates such a (void) signal to take precautions to insure that you don't fall into a hole of unknown depth or hazards, so be sure to rope yourself off to something sturdy before ever starting to dig.
