A woman takes part in the procession of the “Virgem da Atalaia” procession during Holy Week at Alcochete, near Lisbon, Portugal March 27, 2016. Women ride on donkeys during the “Virgem da Atalaia” procession, that has been held annually for about 400 years. In the past, only single women rode the donkeys to ask for help from the Virgin to find a husband. (Photo by Rafael Marchante/Reuters)

The 26th annual National Geographic Traveler Photo Contest is now accepting submissions. Official categories include: “Travel Portraits”, “Outdoor Scenes”, “Sense of Place” and “Spontaneous Moments”. The contest is accepting entries until June 30. Photo: “Forest lights”. Aurora Borealis over the forest of the Pyhae Luosto National Park, Finland. (Photo and caption by Nicholas Roemmelt/National Geographic Traveler Photo Contest)

A wrestler from the Nuba Mountains tribe is seen during a celebration of their cultural heritage, as part of ongoing events to commemorate the International Day of the World's Indigenous Peoples, in Omdurman August 15, 2015. The International Day of the World's Indigenous Peoples is observed on August 9 annually. (Photo by Mohamed Nureldin Abdallah/Reuters)

Alpacas of Lisa Vella-Gatt (not pictured) graze at her farm near Benfeita, Portugal May 11, 2015. Lisa came to Portugal from England in 2009 to set up Monte Frio Alpacas, a project where she breeds alpacas, which produce wool. Lisa's 14 alpacas produce about 50 kilos (110 pounds) of wool annually. (Photo by Rafael Marchante/Reuters)

A boy catches a trout while ice fishing on a frozen river during a fishing contest in Hwacheon, South Korea, Saturday, January 14, 2017. The contest is part of an annual ice festival which draws over 1,000,000 visitors every year. (Photo by /Ahn Young-joon/AP Phot)

A youth stands near a cow and a sheep that were sacrified in the village of Miratovc for the celebration of Eid-al-Adha, near the town of Presevo, southern Serbia September 24, 2015. Muslims across the world celebrate the annual festival of Eid al-Adha or the Feast of the Sacrifice. (Photo by Hazir Reka/Reuters)

A clown checks her phone as she waits outside the Basilica of Our Lady of Guadalupe, in Mexico City, Monday, December 14, 2015. Hundreds of clowns belonging to various clown associations made their annual pilgrimage to the Basilica on Monday to pay their respects to the Virgin of Guadalupe, Mexico's patron saint. (Photo by Rebecca Blackwell/AP Photo)

A woman laughs as she takes part in the “Domingo Fareleiro” (Floury Sunday in Galician) festival in the village of Xinzo de Limia, northwestern Spain, on January 21, 2018. Domingo Fareleiro (Floury Sunday) takes place annually in Xinzo de Limia, Spain, in a unique celebration that gives the starting signal for a long festive period known as Entroido, or Carnival. (Photo by Miguel Riopa/AFP Photo)