Water production in an ancient sarcophagus at Arles-sur-Tech (France)

It has been claimed, from at least the 16th century on, that a sealed sarcophagus, located in the yard of the abbey of Arles-sur-Tech (France), produces hundreds of litres of water per year. Many hypotheses have been advanced to explain this mystery. After about 3 years of data collection, it is concluded that water production, which amounts to about 200 l/year, arises from a balance between rainwater, dew condensation and evaporation. Defects in the sealing provide an exchange with the atmosphere. Condensation is nearly six times greater than evaporation and accounts for about 10% of the total water production.