Red circle seemed to be a cave. White circles where I got signals, depth was able to count down 8-9 feet. If those are tunnels, could be at some point the roof or ceiling is 10 feet deep or perhaps how deep the entrance if concealed with a flat rock door..Also, in countries where you have ancient layers of civilization, deep ruins with valuable artifacts give a signal very similar to a buried treasure. I'm assuming your research has indicated caves/tunnels in the area.