In 1970, Soviet geologists took on the challenge, setting their drills over the Kola Peninsula, which juts eastward out of the Scandinavian landmass. The Kola Superdeep Borehole was just 9 inches in diameter, but at 40,230 feet (12,262 meters) reigns as the deepest hole ever. The earth must be thicker than that, unless it was just a hoax and they did reach the other side, and have kept it from the general public so that no-one attempts to dig a hole for themselves to get to the other side of the world.