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)

People view the sunrise scene at the Bund in Shanghai, east China, January 1, 2017. (Photo by Wang Hechun/Xinhua/Barcroft Images)

A ring-tailed lemur is pictured at Zoom Torino, a zoological park in Cumiana near Turin, on April 22, 2015. Zoom Torino is a new immersive zoological park, where animals can be seen without bars or cages, only natural barriers ensure the visit. (Photo by Marco Bertorello/AFP Photo)

The moon rises over people gathered on Glastonbury Tor ahead of tomorrow's Blue Moon on July 30, 2015 in Somerset, England. The full moon appearing on July 31 will be what's called a Blue Moon, which refers to the second of two full moons appearing in the same calendar month. The last time this happened was in 2012 and there isn't due another until 2018. (Photo by Matt Cardy/Getty Images)

Four-month-old fox cubs squaring up to each other in Walthamstow, England on August 7, 2015. (Photo by Greg Morgan/Barcroft Media)

An Indonesian worker carries a giant candle at a traditional Chinese candle maker for the upcoming Lunar New Year in Bogor, Indonesia, 27 January 2015. The Chinese Lunar New Year, known here as Imlek, is only three weeks away. The whole city is getting decked out to celebrate the event on 19 February 2015. (Photo by Adi Weda/EPA)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

Chefchaouen or Chaouen is a city in northwest Morocco. It is the chief town of the province of the same name, and is noted for its buildings in shades of blue.