A girl laughs while unloading her boat of produce at a market in Ganvie on January 6, 2012 in Cotonou, Benin. Often called the Venice of Africa, Ganvie is a stilted fishing village on Lake Nokoue, near Cotonou in Benin, the largest such village in Africa, and home to approximately 20,000 residents. (Photo by Dan Kitwood/Getty Images)

Visitors of the world's longest tree top walk between the trees of the Bavarian forest on November 6, 2009 in Neuschoenau, Germany. The path, 1300 meters long and in 8 to 25m height, winds up to an impressive tower with a height of 44 meters. The wooden construction is integrated into the forest and delivers a natural experience. (Photo by Miguel Villagran/Getty Images)

Police take part in a role play exercise as they clear a protest on top of a train during training on March 6, 2012 in Oxenhope, England. A new team of specialist officers set up to deal with searches and policing at a height, such as on top of a train, undergo training exercise in Oxenhope, West Yorkshire. (Photo by Bethany Clarke/Getty Images)

A girl allows a butterfly to be placed on her nose at the Sensational Butterflies exhibition at the Natural History Museum on April 6, 2011 in London, England. The exhibition is divided up into five sensory zones exploring how butterflies see, hear, taste, smell and touch. The display containing hundreds of butterflies runs from April 12 to September 11, 2011. (Photo by Peter Macdiarmid/Getty Images)

A Peugeot 408 car is displayed during the 2011 (15th) Shenzhen-Hong Kong-Macao International Auto Show at Shenzhen Convention and Exhibition Center on June 2, 2011 in Shenzhen, Guangdong Province of China. The 6-day Auto Show will be held from June 2 to 7 with total exhibition area of 110,000 square meters. (Photo by ChinaFotoPress/Getty Images)

A Christie's auction house employee wears The Rosebury pearl and diamond tiara, bracelet and brooch on June 6, 2011 in London, England. The jewels, which formerly belonged to Hannah, Countess of Rosebury, feature in Christie's “Important Jewels” sale which take places in London on June 8, 2011. (Photo by Oli Scarff/Getty Images)

Hot air balloons take to the skies over Bristol city centre on August 6, 2012 in Bristol, England. The early morning flight of over twenty balloons over the city was organised as a curtain raiser for the four-day Bristol International Balloon Fiesta which starts on Thursday. Now in its 34th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Matt Cardy)

Anti-bullfighting demonstrators protest against the bulls runs, while standing in cardboard coffins and holding red flowers, on the Ayuntamiento Square in Pamplona northern Spain on Friday July 5, 2013. On July 6, the San Fermin festival will begin with the “txupinazo” , the opening ceremony with people participating in bull runs, music and dance, through the old street of the city. (Photo by Alvaro Barrientos/AP Photo)