Members of a music band rest before the procession of “Nossa Senhora da Boa Viagem”, in Constancia April 6, 2015. This benediction has been held annually for about 200 years. In the past, goods were transported by the Tagus river in small boats to Lisbon, 100 km south. The sailors, as the navigation was dangerous, blessed their boats every year during the festivity of “Nossa Senhora da Boa Viagem”. (Photo by Rafael Marchante/Reuters)

Iranian Kurdish female members of the Freedom Party of Kurdistan (PAK) hold a position on November 6, 2016 in an area near the town of Bashiqa, some 25 kilometres north east of Mosul, during an operation against Islamic State (IS) group jihadists to retake the main hub city. (Photo by Safin Hamed/AFP Photo)

A child walks to an installation made from fallen leaves by college students, in shape of a sofa, to call for people's attention to environment protection, in Hangzhou, Zhejiang province, China, December 6, 2016. (Photo by Reuters/China Daily)

2016 Rio Olympics, Handball, Preliminary, Women's Preliminary Group B Netherlands vs France, Future Arena, Rio de Janeiro, Brazil on August 6, 2016. Lois Abbingh (NED) of Netherlands celebrates a goal. (Photo by Marko Djurica/Reuters)

2016 Rio Olympics, Beach Volleyball, Women's Preliminary, Beach Volleyball Arena, Rio de Janeiro, Brazil on August 6, 2016. Liliana Fernandez Steiner (ESP) of Spain prepares to serve. (Photo by Ruben Sprich/Reuters)

A quake-resistant dome house decorated with Japan's popular “Kumamon” bear character is pictured at the Aso Farm Land resort in Aso, Japan on November 6, 2017. Cabins modelled after Japanese sweets and made from polystyrene foam withstood last year's deadly earthquakes in Kumamoto prefecture. (Photo by Kim Kyung-Hoon/Reuters)

South Asian countries in terms of total contribution of travel and tourism to GDP. #6. Vietnam, Total GDP: USD 202.6 billion (2016). Contribution of Travel and Tourism to GDP: 9.1% . Here: A boat in the Thu Bon River, Hoi An, Vietnam. (Photo by Domingo Leiva/Getty Images)

Participants of the 79th edition of the annual Christmas swimming “Coupe de Noel” jump into the Lake Geneva, in Geneva, Switzerland, Sunday, December 17, 2017. More than 2000 men and women swam the 120 meters at the traditional Christmas swimming in Geneva where the water temperature was 6 degrees. (Photo by Martial Trezzini/EPA/EFE/Rex Features/Shutterstock)