But ground penetrating radar had provided compelling evidence and the following spring he would defrost the specimen with hairdryers in a specially adapted underground cavern.

The stuffy underground cavern lacked windows, natural light and ventilation.

The process created an underground cavern whose roof rose higher as the salt was extracted.

Now a group of amateur treasure hunters claims to have located the loot in an underground cavern.

After checking in at one of 120 kiosks, passengers leave the underground cavern and enter a long, thin space through which they move on the way to their aircraft.