These ingredients of active mining were often left behind when the operation was abandoned. Explosives such as dynamite and blasting caps become very unstable over time and can explode if disturbed. Storage containers, boxes, barrels, and drums deteriorate, allowing toxic chemicals to leak or to combine into highly dangerous mixtures. Not all mines are underground. Open pits can be filled with water which, in turn, can be highly acidic or laden with harmful chemicals.
High walls can be unstable at the top and the bottom and are prone to collapse.
When approached from the top, the vertical edge of a high wall may not be seen in time or may crumble, leading to a fatal fall. Mines can be honeycombed with literally miles horizontal and vertical passageways that randomly follow the original ore veins. Within a short distance of the entrance there is no light, only total blackness. Artificial sources of light such as flashlights and lamps can unexpectedly break or fail, leaving you deep in an underground maze so dark that you cannot see your hand in front of your face. You can cautiously reverse your course in absolute darkness, but you may find many side openings that you had not kept track of on the way in.