A visitor walks inside the initiation well at Quinta da Regaleira in Sintra October 6, 2014. Sintra became the first centre of European Romantic architecture in the 19th century, which influenced the development of landscape architecture throughout Europe. It was classified as a World Heritage Site by UNESCO in 1995. Its monuments are visited by more than 1.5 million of tourists every year, according to local media. (Photo by Rafael Marchante/Reuters)

Egmont National Park in New Zealand with Mt. Taranaki at its center is seen in a Landsat 8 satellite image taken July 3, 2014 and released by NASA November 14, 2014. The image is from the book “Sanctuary: Exploring the World's Protected Areas from Space”, published by the Institute for Global Environmental Strategies with support from NASA, which was released this week. (Photo by Reuters/NASA/USGS)

An aerial view of a livestock enclosure of the Himba people, in October, 2014, in the Namib Desert, Namibia. A photographer has captured a bird's eye view of the stunning Namib Desert from a paraglider. Theo Allofs travels the world taking stunning pictures of untouched landscapes from a unique perspective. Soaring 300 metres above ground, Theo shot the yellow sand dunes, dry red river beds and remote townships in Namibia. (Photo by Theo Allofs/Barcroft Media)

World War II veteran Jack W. Schlegel, 91 years-old, from Mount Tremper, New York, of the 508th Parachute Infantry Division of the 82nd Airborne who parachuted near Sainte-Mere-Eglise on June 6,1944, poses with American and French flags as he visits the American War cemetery in Colleville-sur-Mer, on the Normandy coast June 2, 2014. REUTERS/Pascal Rossignol

An enormous crocodile mauls a young hippo calf carcass near Lower Sabie on May 11, 2014, in Kruger National Park, South Africa. An enormous crocodile tosses around a young hippo calf caught in its lethal jaws. The giant reared out of the water revealing a young hippo calf between its teeth. The huge beast then span, jumped and splashed in the water with the small carcass. Amateur photographer Roland Ross captured these incredible photographs near Lower Sabie in Kruger Park, South Africa. (Photo by Roland Ross/Barcroft Media)

Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. (Photo by Ruben Sprich/Reuters)

Sarah Gibbons grades a new batch of Maple Syrup at Gibbons Family Farm in Frankville, Ontario, Canada, 31 March 2014. The annual maple syrup season marks the end of the often brutal central Canadian winters and heralds the beginning of spring. The maple tree, whose leaf dominates the Canada's flag, plays both a symbolic and practical role in the identity of Canadians who produce around 95 percent of the world's supply of maple syrup. (Photo by Stephen Morrison/EPA)

Ximena Rivero of Peru competes in the South American Pole Dance Championship in Buenos Aires November 24, 2014. Participants from throughout South America will be vying for the top spots in the two-day competition, with the winners qualifying for the 2015 World Pole Dance Championship in Hong Kong. (Photo by Enrique Marcarian/Reuters)