Without a doubt, the Samaesan Hole in Thailand’s Samaesan Bay is the most dangerous cave in the world. Imagine diving deep into a cave with unexploded bombs! That’s because the hole is a former military dumping ground. Besides this, what makes the Samaesan Hole so dangerous is the fact that it penetrates 85 meters deep into the earth. To top that, the cave faces incredibly strong currents, which could take divers severely oﬀ course if they aren’t prepared. This deep dive site in the Gulf of Thailand plummets almost 280 feet, and sunlight rarely reaches the bottom.