They usually hit the headlines for swallowing cars, houses and occasionally whole streets.
But this particular sinkhole in Oman is so stunning it has been turned into a tourist attraction.
The beautiful limestone hollow, in Bimmah, boasts the kind of clear waters normally only seen on holiday postcards.
While similar holes engulf residential streets or open up in front of despairing home owners, the Bimmah sinkhole has long been attracting tourists eager for a picturesque swim.
Visitors are regularly spotted at the Oman site taking a dip in the vibrant emerald-
Sinkholes are found worldwide, and can form suddenly or over time, ranging in size from just one metre wide to 600m in size.
The ground beneath the holes is normally made of easily-
When groundwater flows through these rocks, it eats away at the rock, leaving behind subterranean holes and caverns.
When the roof of one of these caverns collapses, the land above it falls in too, leaving giant holes such as the one in Oman
GPS: 23.035843, 59.071988