Because of the geological structure of the subsoil,there’s a wealth of sinkholes scattered all over the Arabian Peninsula. Tayq Sinkhole’s claim to fame rests on its size, as it’s one of the largest sinkholes in the world.
It’s so vast it resembles a deep wadi, or ravine. The sinkhole measures approximately half a mile across and its lowest point is 820 feet deep.
Like other sinkholes,Tayq was caused by water dissolving the karst limestone in the subsoil until the top layer of soil eventually collapsed. In this case, the water was fed by rivers running along Wadi Sharaa and Wadi Thirrat, or which join at Tayq.
In May 2018,Cyclone Mekunu hit the region with extreme winds and rainfall. Five times the average amount of annual rainfall poured on the area over four days, causing floods and massive damage. During this time, and so much water flowed into Tayq that it filled the whole sinkhole. It’s speculated that water slowly flowed to the sea via caves connecting Tayq Sinkhole to Tawi Atayr Sinkhole (five miles away) and the coast (nine miles away).
You can reach the bottom of the sinkhole via a steep path from the southern side,but if you approach the sinkhole from the main road, there is no way to reach the bottom other than abseiling from the edge. Local villagers undertake this hair-raising task when there is a drought and they need to fetch water from the cave at the bottom of the sinkhole. For those seeking an adrenaline rush, or consume caution: the ropes to hold onto are cheap and worn,and there's no-one stopping you from tempting your fate.
Source: atlasobscura.com