Engine driver Josef Kowatsch (top L) steers a train through the NEAT Gotthard Base Tunnel during a media visit near the town of Erstfeld August 24, 2015. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016, consisting of two parallel single track tunnels, each of a length of 57 km (35 miles). (Photo by Arnd Wiegmann/Reuters)

A makeshift cart with containers is seen at a suspected drug tunnel under construction during a media tour by Mexican Army in Tijuana April 7, 2015. Mexican soldiers foiled the construction of a suspected drug tunnel underneath a house near the U.S. border, arresting nine people and impounding a truck used to clear debris, the Army said on Tuesday. Wired with lights, the tunnel was being built next to the Tijuana border crossing, south of San Diego, California, and near a Mexican air force installation as well as a regional federal police facility. (Photo by Reuters/Stringer)

The waning moon is setting over the mountain “Les Cornettes de Bise” located at the border of the Haute-Savoie and the Valais canton of Switzerland in the Chablais Alps, photographed from Glutieres, January 7, 2015. (Photo by Anthony Anex/EPA)

In this Wednesday, January 27, 2016 photo, Jung Myoung Sook, 61, holds her puppies she rescued at a shelter in Asan, South Korea. In the country, where dogs are considered a traditional delicacy and have only recently become popular as pets, Jung's love for her canine friends is viewed by some as odd. But others see her as a champion of animal rights. (Photo by Lee Jin-man/AP Photo)

Giant panda Meng Meng plays on a tree at a Siberian tiger-breeding base in Changchun, China on December 10, 2015. (Photo by Xu Chang/Xinhua Press/Corbis)

Aymara indigenous women “Martha La Altena” (El Alto's Martha) (R) and “Susana La Bonita” (Pretty Susana) take part in a freestyle wrestling flight in El Alto, on June 29, 2018. “Cholita Fighters” aim to include their show in a tourist route. (Photo by Aizar Raldes/AFP Photo)

Balinese I Ketut Widanta or known as Lelut rides to collect fodder with his dogs sits on his motorbike in Canggu, Bali, Indonesia on November 05, 2021. Lelut becomes famous for his attractive style of carrying six of his rescued dogs with a modified motorbike while collecting food waste from restaurants. Currently, he takes care of twenty rescued dogs which some of them were dumped by the owners on the street due to the Covid-19 pandemic. Often he receives dog food donations from dog lovers since the collapse of Bali tourism affects his income. (Photo by Johannes P. Christo/Anadolu Agency via Getty Images)

Christian Balderosdasco, 31, is being pulled up a mud pit after diving for 3 hours to look for gold on March 22, 2017 in Paracale, Philippines. Apart from tunneling and sifting sand, locals dive down murky swamps with the aid of a compressor with air flowing in a small tube for breathing, as they blindly swim under the mud for up to four hours to look for tiny rocks containing gold particles. For decades, local residents at Paracale town work in hazardous conditions scavenging under the earth and diving into tunnels filled with mud using only makeshift tools to mine for gold, often placing their health and lives at risk. (Photo by Jes Aznar/Getty Images)