Google Earth has provided archaeological researchers and investigators a very powerful tool for looking at any part of the Earth for hidden sites buried under mud, snow or forests. Looking at the oceans, the satellite service even maps the bottom of the ocean so accurately in a way only military subs may have had access to before access to satellite mapping was opened to the public. Underneath the ocean, there are tunnel like structures interconnected into submerged cities. They do not look man-made either.