Certain places are better left unexplored. The natural world, while beautiful and thrilling, can kill. Preparedness, wilderness acumen, and general common sense may be enough to see intrepid travelers through in most situations, but not all. Some pockets of creation are just flat-out lethal. The following list highlights some places that explorers have every reason to fear.

4. Second Beach, Port St. John’s, South Africa

The southern tip of the African continent is, by and large, a gorgeous region to see and experience. A well-known vacation retreat for the ultra-wealthy, South Africa’s Port St. John’s is no exception. Geography makes the town’s Second Beach a popular spot to surf, swim, and enjoy general beach activities. Framed by rocky cliffs, the ocean itself is shallow out to several hundred yards offshore. It then drops off sharply, producing spectacular waves that consistently draw surfers. Why, then, does this attractive beach destination make our list of the four most naturally dangerous spots on Earth?

In a word, sharks. At first look, Second Beach’s 8 attacks in the past 8 years don’t seem all that forbidding in comparison to truly high-volume shark attack beaches, like New Smyrna in Florida. What’s terrifying is that all 8 of these attacks have turned fatal. Fatalities resulting from bites are very rare worldwide, given that sharks typically take a quick bite, realize they’ve misjudged, and leave. At this point, there’s a strong enough sample size from Second Beach to conclude that these sharks are attacking to kill.

One possible explanation? The high frequency of great whites in the area has given rise to a flourishing commercial cage diving industry. Experts believe that the frequent contact between sharks and humans in this setting has triggered a human equals food association in the local predators. Whatever the cause, the evidence points clearly to the idea that the sharks in the waters off Port St. John’s are becoming man-eaters.