A sinkhole is a deep pit under water. The world’s deepest underwater sinkhole is found in the South China Sea.
8. Underwater River
Some oceans have scary and terrifying river type of water bodies underwater. A secret under water river is located in the Yucatan Peninsula in Mexico, called as Cenote Angelita (Spanish for Little Angel). It is a unique view that has a thin layer of hydrogen sulfate that separates the salt water from the fresh water above it.
9. Tire Graveyard
Osborne Reef is an artificial reef in Florida. It is constructed of concrete jacks in a circle of 50 ft diameters. The reef is one of the terrifying things as an environmental disaster as it is dumped with a uncountable number of used and discarded tires.