Carrion

This achievement is for breaching (completing) the Hazardous Waste Landfill. It's a sub-level you will find beneath the Military Junkyard in Carrion. This level in inaccessible until you complete the Uranium Mines and unlock the ability to smash wood. Once you have this ability you will need to backtrack through the Military Junkyard to the area beneath the third hive. In this area you can break wood to reach the Hazardous Waste Landfill.
Credit goes to "enricofairme" from hard to reset; you can find his/her full guide here: https://holdtoreset.com/hazardous-waste-landfill-carrion-gui...