Template:Going deep geohash
To get the Going deep geohash achievement you must reach the geohash location at a point that puts your entire body beneath the local surface of the earth, either via a preexisting hollow such as a cave, sewer, basement or subway line, or by tunneling. As GPS units do not work underground you may need an alternate means of verifying the geohash.
If you choose to tunnel to the geohash, be sure to check with local utility companies for the presence of electrical, gas, fiber optic or other services that could be interrupted by your excavation. Take proper precautions in shoring your tunnel and backfilling it or otherwise securing local terrain when you are done with it.