If you were like most people when they were young, you likely said at one point that you were going to dig down to the other side of the Earth. This is a fun challenge that is taken up by children around the world, though none have so far achieved the goal.

When thinking back on those types of fond memories from childhood, you might wonder just how deep people can actually dig.

Well, the answer so far can be found at the Kola Superdeep Borehole in Russia.

Back in the 1960’s the Cold War was going on, and anything that either the United States or Russia did, the other country seemed to want to try to outshine it. That is where we got the space race, and many other major projects.

When the US started a project with the goal of drilling as deep as possible into the a hole in the Mexican Pacific, the Soviet Union took on the challenge.

They began drilling on May 24, 1970 and kept on drilling until 1992. During that time, their dig site became the deepest hole any human has ever dug.

How deep did they get?

Well, the project actually consisted of multiple different holes that branched off from the main central hole. The one that went the deepest was named SG-3 and it went down 12,263 meters (40,230 feet).

That is a remarkable accomplishment.

To put it in perspective, this hole goes down as far as Mt. Everest and Mt. Juji on top of each other would go up. The hole is deeper than the Mariana Trench, which is the deepest known point in the ocean.

So, it is deep.

Shortly after the collapse of the Soviet Union, the project was stopped because of political issues, cost problems, and more technical issues. Specifically, the temperature that deep was much hotter than experts at the time expected.

At the bottom of the hole, temperatures were reported to be 180° C (356°F), which was too hot for most types of drilling equipment.

The project has been long abandoned now, and there are even reports that the hole has been at least partially filled in, but during its time it did help provide a lot of information to scientists. They found that water existed much deeper than believed to be possible. There were also microscopic organisms fossilized at these depths.

It is unlikely that humans will take on this type of project again anytime soon, but if (or when) we do, it is almost certain that it would help to further our understanding of how our planet really works.