10. The Singing Rocks of Pennsylvania
On a hill in Pennsylvania, there is a field that contains rocks. Nobody knows where they came from and how they ended up there. There is no higher mountain or cliff nearby ruling out the possibility that they could’ve fallen through landslide.
But that’s not even the strangest part. When you strike any of these rocks, they made a sound… yes, a musical sound! Investigators have revealed that the rocks are making these sounds on their own. When a single rock is hit, it lets out a tone that cannot be heard by human ears. But when you put two rocks near each other and strike them, their tones interact and we can actually hear them.
These rocks have also encouraged alien enthusiasts who believe that these are not from our world. Either they come from an alien planet or they are debris of an alien spaceship.