An Omani woman prepares for a traditional dance during a ceremony attended by Britain's Prince Charles and his wife, Camilla, Duchess of Cornwall in Muscat, Oman, Saturday, November 5, 2016. The royal couple have started a three-nation royal tour of the Gulf in Oman. (Photo by Kamran Jebreili/AP Photo)

People attend a Halloween event at Ocean Park on October 30, 2015 in Hong Kong. Halloween – a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1 – a holiday when Christians remember their deceased loved ones. (Photo by Anthony Kwan/Getty Images)

An Indian man stands dressed like Hindu god Shiva to attract alms from devotees during the Ambubasi festival at the Kamakhya Hindu temple in Gauhati, India, Sunday, June 22, 2014. The annual festival where hundreds of holy men from an esoteric form of Hinduism, gather to perform rituals at the temple begins on June 22. (Photo by Anupam Nath/AP Photo)

The summit of one of Europe's tallest mountains glows like the flame of a candle as the sun rises on a clear morning. The Matterhorn, famous for appearing on bars of Toblerone chocolate bars, reflects the vivid orange light at 5.37am. (Photo by Margarethe Jaeger/Solent News & Photo Agency)

Merit: A Night at Deadvlei. The night before returning to Windhoek, we spent several hours at Deadveli. The moon was bright enough to illuminate the sand dunes in the distance, but the skies were still dark enough to clearly see the milky way and magellanic clouds. Deadveli means “dead marsh. The camelthorn trees are believed to be about 900 years old, but have not decomposed because the environment is so dry. (Photo and caption by Beth McCarley/National Geographic Traveler Photo Contest)

A girl plays with colourful papers at the 23rd Sziget (Island) Festival on Shipyard Island in Budapest, Hungary, 13 August 2015. The festival is one of the biggest cultural events of Europe, offering art exhibitions, theatrical and circus performances and music concerts. Almost 200 performers from 47 countries will entertain the hundreds of thousands of visitors from 11 to 18 August. (Photo by Balazs Mohai/EPA)

A municipal police officer throws a stone back at protesting residents of Kampung Pulo after clashes erupted during an eviction in Jakarta, Indonesia, August 20, 2015 in this photo taken by Antara Foto. Residents facing eviction from a flood-prone part of Indonesia's capital of Jakarta clashed with police on Thursday, prompting security forces to fire tear gas and water cannon. (Photo by Muhammad Adimaja/Reuters/Antara Foto)

Nubian women sell traditional handicrafts at the Nubian Gharb Suheil village, near Aswan south of Egypt, October 1, 2015. For half a century, Egypt's Nubians have patiently lobbied the government in Cairo for a return to their homelands on the banks of the upper Nile, desperate to reclaim territory their ancestors first cultivated 3,000 years ago. (Photo by Mohamed Abd El Ghany/Reuters)