Revellers celebrate "Ash Monday" by participating in a colourful "flour war", a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter,in the port town of Galaxidi, some 215 km (134 miles) north west of Athens, March 18, 2013. The revellers "fight" by throwing coloured flour, charcoal dust and powder painting until they essentially run out of supplies. (Photo by Yannis Behrakis/Reuters)

A model poses with “The Wellbeing Toilet” the winning entry from a Dyno-Rod Initiative to create a new design for the domestic toilet at Central Saint Martins on November 18, 2013 in London, England. The concept was commissioned to mark 50 years of Dyno-Rod and World Toilet Day on November 19th, 2013 The “Wellbeing Toilet” looks at the health and wellbeing aspect of getting rid of your bodily waste by being sculpted to enhance the position of your body by enabling you to squat rather than sit. (Photo by Miles Willis/Getty Images for Dyno-Rod)

“Thor Heyerdahl (October 6, 1914, Larvik, Norway – April 18, 2002, Colla Micheri, Italy) was a Norwegian ethnographer and adventurer with a background in zoology and geography. He became notable for his Kon-Tiki expedition, in which he sailed 8,000 km (4,300 miles) by raft from South America to the Tuamotu Islands. All his expeditions are shown in the Kon-Tiki Museum, Oslo”. – Wikipedia

Photo: Norwegian anthropologist Thor Heyerdahl with a model of the balsa raft “Kon-Tiki” on which he drifted 4,300 miles from Peru to the Tuamotu Islands, proving his theory that Polynesia could originally have been populated by South Americans. (Photo by Express/Express/Getty Images). 1950

Belarusians wearing national costumes celebrate a Pull the Kolyada Up the Oak rite in the village of Martsiyanauka, some 77 km (48 miles) east of capital Minsk, Belarus, Thursday, January 21, 2016. The merry ancient rite Pull the Kolyada Up the Oak marks the end of Orthodox Christmas celebrations in Belarus. On Jan. 21 a wheel, the so-called Kolyada, would be pulled up an oak or any old tree. The Belarusians believed that the ritual heralds a good harvest, luck and happiness for the entire year. (Photo by Sergei Grits/AP Photo)

Yanelis Blanco, 24, center, dances with a group of friends at Santa Maria beach, about 15 miles from Havana. It is the closest beach to Havana. Others, from left to right are Jackson Miranda, 21, Dayan Suarez, 24, and Melisa Oliva, 15. The men in the group have a rap group together. The government is demolishing buildings all over the coast of East Havana and recovering and restoring beach dunes. (Photo by Sarah L. Voisin/The Washington Post)

A man holds a girl as she tries to escape when she realised she is to to be married, about 80 km (50 miles) from the town of Marigat in Baringo County, Kenya, December 7, 2014. As Pokot tradition dictates, the future husband arrived to her family home with a group of men to collect the girl. The men arrived with the last settled dowry of livestock for the girl's family. In this case it was 20 goats, three camels and 10 cows, given during a period of several weeks. (Photo by Siegfried Modola/Reuters)

Al-Shamiyah Front fighters inspect a new locally-made cannon named “Borkan” (Volcano) as it was being launched towards forces loyal to Syria's president Bashar Al-Assad located in Aleppo artillery school, March 7, 2015. The “Borkan” is made out of four tubes attached to a loader, which can fire four shells at a time, and have a range of three kilometers (1.86 miles). (Photo by Abdalrhman Ismail/Reuters)

Mount Sinabung, a highly active volcano on Sumatra island, erupted several times this week. A volcanology agency has declared a danger zone of about four miles from the crater after seven farmers were killed and two others seriously injured. Here: A man carries his dog as a giant ash cloud rises from the Sinabung volcano in Karo, Indonesia on May 26, 2016. (Photo by Sutanta Aditya/Barcroft Images)