Oman’s Most Beautiful Sinkhole

Incredible Sinkhole in Oman. Image via the Daily Mail

Tourists flock to this 20-meter well of crystal-clear water.

Sinkholes are formed when groundwater slowly dissolves layers of porous rock like limestone, digging out an underground cave in the earth. Eventually, the roof of the cave collapses, creating a massive hole in the landscape that soon fills with cool, clean water filtered by the soil.