Everyone who lives near Naples has heard of the Grotta del Cane (Dog Cave) at least once, and many have been to it. The cave's fame is built on the bones of dogs belonging to overly curious owners. A person could freely enter and exit it, but his four-legged companion could not. And the longer the animal was in the cave, the greater the chance that it would die.
This place has been known for a long time. In the 20th century, people talked about evil spirits hiding from the sunlight in the darkness of the dungeon, which strangled dogs. In a way, the superstitions were true. The dogs were really strangled, but not by evil spirits, but by a natural anomaly.
Today it is known that the Dog Cave produces carbon dioxide, which accumulates 80 cm above the ground. The human head is in the air layer, and the dog's head is in the atmosphere of the deadly gas. But the animal does not die immediately. First, the reactions slow down, then the loss of consciousness occurs, and if the dog is not promptly raised, but rather taken out into fresh air, then it will die.
Due to a series of bad events, the ill-fated cave is a popular destination among tourists. But many people forget that it is dangerous not only for dogs, but also for a person who, for example, squatted down to tie his shoelaces or take some good shots … Depending on the state of health, some may lose their lives faster than planned. That is why it is not recommended to visit this place alone.