A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

A man looks at kebabs cooking on the street side in Rawalpindi, Pakistan October 2, 2017. (Photo by Caren Firouz/Reuters)

Chinese workers maintain an Animatronic Dinosaurs at Gengu Dinosaurs Science and Technology company on November 13, 2019 in Zigong, Sichuan Province, China. There are hundreds of simulated dinosaur manufacturers in Zigong City. It is the largest simulated dinosaur manufacturing in China. It accounts for 95% of mainland China's production and 85% of the world's total. Its products are exported to more than 100 countries. (Photo by Lintao Zhang/Getty Images)

A young Sikh boy shouts religious slogans during a procession ahead of the birth anniversary of Guru Nanak in Jammu, India, Wednesday, November 21, 2018. The birth anniversary of Guru Nanak, founder of Sikhism and first Sikh guru, will be marked on Nov. 23. (Photo by Channi Anand/AP Photo)

Dancers resting on the rooftop of the SKD Theatre Asakusa, Tokyo, 1949. (Photo by Tanuma Takeyoshi/The Guardian)

A bride and groom jump over a skipping rope as they pose during a wedding photo shoot at a park in Pyongyang on April 18, 2019. (Photo by Ed Jones/AFP Photo)

Competitors take part in the 8th annual World Gravy Wrestling Championships at the Rose n Bowl Pub in Bacup, north west England on August 31, 2015. Contestants must participate in fancy dress and wrestle in a pool of Lancashire Gravy for 2 minutes whilst being scored for a variety of wrestling moves. (Photo by Oli Scarff/AFP Photo)

A pine marten – one of a few wild mammals doing well in Britain (although they number just 3,700). A fifth of the country’s wild mammals are at high risk of extinction, research shows. (Photo by Maurice Flynn/The Mammal Society)