In this March 12, 2015 photo, a man tours a graffiti exhibition at the Museum of Modern Art, in Bogota, Colombia. The city-run museum recently held an exhibition highlighting the work of Bogota street artists who go by aliases such as Joems and the MonsTruacioN collective. (Photo by Fernando Vergara/AP Photo)

Employees of the Park Royal resort wait for a shuttle to take them to work early in the morning on April 2, 2015 in Acapulco, Mexico. Despite problems with cartel violence Semana Santa is one of the biggest tourist weeks of the year in Acapulco, a city whose entire economy depends on tourism, and officials expect around 350,000 mostly Mexican visitors this week. (Photo by Jonathan Levinson/The Washington Post)

Star Wars actors on the Cantina set at Star Wars Celebration: The Ultimate Fan Experience held at the Anaheim Convention Center on Thursday, April 16, 2015, in Anaheim, Calif. (Photo by Richard Shotwell/Invision/AP Photo)

Villagers use a makeshift bamboo bridge to move across flooded areas of Morigaon district in the northeastern Indian state of Assam August 20, 2014. The latest heavy rains have caused landslides and floods in many parts of India and Nepal, where at least 90 people have been killed since Thursday. (Photo by Reuters/Stringer)

NYC morning fog. Wednsday, January 15, 2014, morning dense fog creates spectacular views over the East river of lower Manhattan, Brooklyn and Manhattan bridges as New Yorkers and tourist admire the scenery. View from Brooklyn Bridge Park in DUMBO Brooklyn. (Photo by Paul Martinka/New York Post)

Traveling Chairso n Hakone Road. (Photo by Kusakabe Kimbei)

A rail worker fixing a fog warning notice at South Woodford Railway Station in Essex. (Photo by H. F. Davis/Topical Press Agency/Getty Images). 20th October 1938