Majlis al-Jinn, a vast cavern on Selma plateau, was closed to the public this year after one daredevil too many parachuted into the 150m-deep cave, a stunt that has often been performed as part of corporate promotions.

The Oman government now plans to turn the cave into an eco-resort and tourist attraction. And one of the entrances to the world’s eighth largest cave chamber will be reserved for base-jumping.