The world's most spectacular sinkholes, from Turkmenistan's Gates of Hell to Oman's Tawi Atair

An enormous sinkhole, about 32 metres wide and twice as deep, appeared near a copper mine in Chile, leading experts to investigate what caused it.

So what leads to these great holes in the earth?

Many are marvels of nature. According to National Geographic, natural sinkholes appear when soft underground rock under land is easily dissolved — usually by running water or rain.

Man-made sinkholes are typically found in urban centres, where development including buildings and roads compromises the underlying rock it had been built on.

According to the US Geological Survey, trapped rainwater plays its part. Sinkholes cased by rain are common in East Asia and can be deadly.

Geologists say it is hard to predict when the top layer of rock will collapse. The USGS estimates that sinkholes caused $300 million of damage a year in the US, but that figure could be higher.

UAE finds a sinkhole

In 2021, a blue hole was discovered off the coast of Abu Dhabi in the Arabian Gulf which measured around 12 metres deep and 2,000 metres wide.

The rare underwater sinkhole was found just off Al Dhafra but it pales in size to the deepest blue hole, Dragon Hole, which lies in the South China Sea and reaches around 300 metres beneath the seabed.

Oman's lush green sinkholes

Shrouded in fog, the enormous Tawi Atair sinkhole is one of four that dot Dhofar governorate in southern Oman

Tawi Atair means “Well of Birds” in Dhofar's regional language, a reference to the avian twittering, distorted by echoes, that reverberates off the rock.

Now the sinkholes are marketed as a tourist attraction in Dhofar.

Yemen's 'Well of Hell'

The Oman sinkholes are not to be confused with the “Well of Hell”, or Well of Barhout, the foul-smelling, pitch-black Barhout pit across the border in eastern Yemen that is reputed as a prison for demons.

The giant hole in the desert of Al Mahra province is 30 metres wide and thought to be anywhere between 100 and 250 metres deep.

Take a look at some of the most spectacular sinkholes in the photo gallery above by clicking on the arrows. If using a mobile device, simply swipe. Learn more about some of the sinkholes mentioned in The National stories below.