Ultra- trailers compete at sunrise on September 2, 2017 in Courmayeur, Italy, during the 15 th edition of the Mount Blanc Ultra Trail (UTMB), a 170 km race around the Mont Blanc crossing France, Italy and Switzerland. The 15 th Ultra- Trail du Mont- Blanc (UTMB) is a mountain ultramarathon with numerous passages in high altitude (>2500 m) and in difficult weather conditions (night, wind, cold, rain or snow). (Photo by Jeff Pachoud/AFP Photo)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

People dressed as ancient Roman reflect on a helmet during a parade to mark the anniversary of the foundation of Rome in 753 BC, on April 23, 2017 in Rome, Italy. (Photo by Alberto Pizzoli/AFP Photo)

Mount Etna, Europe's most active volcano, is seen from the side of a road as it spews lava during an eruption in the early hours of Thursday, March 16, 2017. Sicily's Mount Etna volcano unleashed an explosion Thursday, hurling molten rocks and steam that rained down on tourists, journalists and a scientist who scrambled to escape the barrage. Ten people were reported injured. (Photo by Salvatore Allegra/AP Photo)

A tourist stands in front of Italy's Mount Etna as it spews lava during an eruption on the southern island of Sicily, Italy on March 1, 2017. (Photo by Antonio Parrinello/Reuters)

A masked reveller poses during the Venice Carnival in Venice, Italy February 17, 2017. (Photo by Alessandro Bianchi/Reuters)

A masked reveller poses during the Venice Carnival in Venice, Italy February 12, 2017. (Photo by Tony Gentile/Reuters)

Masked revellers pose during the Venice Carnival in Venice, Italy February 11, 2017. The Venice carnival in the historical lagoon city attracts people from around the world. (Photo by Tony Gentile/Reuters)