A volcano—even an undersea volcano—might not seem like the best place to hang out. The water is notably hot, even when the volcano’s not erupting, acidic, and bubbling with gas.

One such underwater volcano, Kavachi, near the the Solomon Islands, has not been much explored, because it’s dangerous to get anywhere near it and difficult for divers to tolerate the heat. But, as National Geographic reports, recently Brennan Phillips, a oceanographic engineer, and his team used underwater robots and cameras to dive deep into the volcano, and they found something unexpected—sharks. 

“These large animals are living in what you have to assume is much hotter and much more acidic water, and they’re just hanging out,” Phillips told National Geographic.

These were hammerheads and silky sharks, and the fact that they seemed perfectly happy in the volcano’s presumably scorching waters raised one pretty big and as-of-yet unanswered question: How do they do it? 

Bonus finds: Rodin statue stolen 24 years ago, giant starfish

Every day, we highlight one newly lost or found object, curiosity or wonder. Discover something unusual or amazing? Tell us about it! Send your finds to [email protected].