In this Wednesday, March 18, 2015 photo, limestone quarry workers walk through a cloud of dust spewed into the air by rotor blades of the stone-cutting machinery in the desert of Minya, southern Egypt. Around 45,000 people, including children, work in an estimated 1,500 quarries, digging out stones that later will be used in construction or powdered to be used by pharmaceutical and ceramic companies. (Photo by Mosa'ab Elshamy/AP Photo)

Floating on clear deep water and reflections near the cave entrance. Visitors can either bring their own kayaks or rent boats from the local community to paddle deep inside the cave and marvel at its wonders on March 2015 at Tham Khoun Ex, Laos. Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water. Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water. The cave is formed by the Xe Bang Fai river, a major tributary of the Mekong and in the dry season can be traversed using inflatable kayaks. (Photo by John Spies/Barcroft Media/ABACAPress)

Men rest after salvaging metal on the 30th floor of the “Tower of David” skyscraper in Caracas February 3, 2014. A 45-storey skyscraper in the center of Venezuela's capital Caracas is a slum, probably the highest in the world. Dubbed the “Tower of David”, the building was intended to be a shining new financial center but was abandoned around 1994 after the death of its developer – banker and horse-breeder David Brillembourg – and the collapse of the financial sector. (Photo by Jorge Silva/Reuters)

Sun Model students pose for a photo during a training session at the school on March 31, 2014 in Phnom Penh, Cambodia. Having started in August 2010 with only three models, the Sun Model Agency and School is starting to make an impact in the fashion industry in Cambodia. (Photo by Omar Havana/Getty Images)

Members of an American landing party assist troops whose landing craft was sunk by enemy fire off Omaha beach, near Colleville sur Mer, France, June 6, 1944. REUTERS/Weintraub/US National Archives

An athlete pulls a 15-tonne truck during a Truck-Pull event marking the upcoming Independence Day in the Belarus capital Minsk, on July 3, 2014. The former Soviet nation celebrates its Independence Day on July 3 in memory of the end of Belarus occupation by Nazi Germany troops during the Red Army main summer offensive in 1944. (Photo by Sergei Gapon/AFP Photo)

Model, skydiver and wing-suit jumper Roberta Mancino, 33, swims with a whale shark on February 2014 in Isla Mujeres, Mexico. A female skydiver swims with whale sharks, manta rays and sailfish – the fastest fish in the sea. Model, skydiver and wing-suit jumper Roberta Mancino, 33, jumped from a boat into the ocean surrounding Isla Mujeres near the northern Peninsula of Mexico. The incredible project involved two trips to the stormy winter seas – one in February 2013 and one a year later in February 2014. (Photo by Shawn Heinrichs/Barcroft Media)

An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)