(Photo: Juozas Šalna)
This is the Bimmah Sinkhole, a natural swimming pool in Oman. As the name suggests, it’s formed by the erosion and collapse of a level of limestone in the Hawiyam Najm Park.
Visitors can swim and relax in the cool blue waters that are almost transparent.
This is one of 18 astonishingly lovely natural swimming spots rounded up by When on Earth. Have you visited any of them?