Women wearing traditional hats, known as a non la, sell fruits in Hoi An, Vietnam April 4, 2016. The non la hats are made of readily available materials such as palm leaves, tree bark and bamboo and are visible everywhere in the city, a UNESCO World Heritage site. Hoi An's history as a busy trading port is evident throughout its architecture, a mix of eras and styles, with traditional wooden Vietnamese houses, Chinese temples and French colonial buildings. (Photo by Jorge Silva/Reuters)

Maria, 18, wearing a traditional Sevillana outfit, poses for a portrait during the traditional Feria de Abril (April fair) in the Andalusian capital of Seville April 16, 2013. (Photo by Marcelo del Pozo/Reuters)

Salar de Uyuni (or Salar de Tunupa) is the world's largest salt flat at 10,582 square kilometers (4,086 sq mi). It is located in the Potosí and Oruro departments in southwest Bolivia, near the crest of the Andes, and is elevated 3,656 meters (11,995 ft) above mean sea level. The Salar was formed as a result of transformations between several prehistoric lakes. It is covered by a few meters of salt crust, which has an extraordinary flatness with the average altitude variations within one meter over the entire area of the Salar.

An environmental activist performs during a protest in front of the headquarters of Brazilian mining company Vale SA in downtown Rio de Janeiro, Brazil, November 16, 2015. The collapse of two dams at a Brazilian mine, owned by Vale SA and BHP Billiton Ltd, has cut off drinking water for quarter of a million people and saturated waterways downstream with dense orange sediment that could wreck the ecosystem for years to come. Nine people were killed, 19 are still listed as missing and 500 people were displaced from their homes when the dams burst at an iron ore mine in southeastern Brazil on November 5. (Photo by Sergio Moraes/Reuters)

A Rafale fighter jet flies over France's Charles de Gaulle aircraft carrier as it makes its way in the Gulf, January 28, 2016. (Photo by Philippe Wojazer/Reuters)

A child dressed as a clown takes part in the celebration of the Virgen de los Desamparados, or Our Lady of the Abandoned, at Diria town, Nicaragua May 14, 2016. (Photo by Oswaldo Rivas/Reuters)

Masked penitents holds their crosses during spring “Romeria Cruceros de Arce”, in Roncesvalles, northern Spain, Sunday, May 10, 2015. Every year on the second Sunday in spring, people with crosses march from their small Pyrenees towns to Roncesvalles Church in tribute of the Virgin. (Photo by Alvaro Barrientos/AP Photo)

A “Maya” girl sits in an altar during the traditional celebration of “Las Mayas” on the streets in Colmenar Viejo, near Madrid, Spain, Friday, May 2, 2014. The festivity of the Maya comes from pagan rites and dates from the medieval age, appearing in ancient documents, it takes place every year in the beginning of May and celebrates the beginning off the spring. A girl between 7 and 11years is chosen as “Maya” and should sit still, serious, and quiet for a couple of hours in an altar on the street decorated with flowers and plants, afterwards they walk to the church with their family where they attend a ceremony. (Photo by Daniel Ochoa de Olza/AP Photo)