View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)

Some 300 girls and women in India still practise open defecation. Over half the country’s population, 800 million people, do not have access to a toilet that meets basic standards. (Photo by Poulomi Basu/WaterAid)

Every year National Parks Week gives visitors a chance to celebrate the incredible woodland spaces around the UK. This year the National Parks Week runs from 28 July – 3 August and there are 10 national parks across England to explore. Each one has created a special event to celebrate the National Parks Week, from picnics and treasure hunt in the park to cycle rides, safari or outdoor art exhibition. (Photo by Diana Jarvis/VisitEngland)

An adult chimp plays with a young chimp at Chimp Haven in Keithville, La., Monday, February 18, 2013. One hundred and eleven chimpanzees will be coming from a south Louisiana laboratory to Chimp Haven, the national sanctuary for chimpanzees retired from federal research. (AP Photo/Gerald Herbert)

An Indian bride, sits during a mass marriage of 162 Muslim couples in Ahmadabad, India, Sunday, March 3, 2013. Mass marriages in India are organized by social organizations primarily to help the economically backward families who cannot afford the high ceremony costs as well as the customary dowry and expensive gifts that are still prevalent in many communities. (Photo by Ajit Solanki/AP Photo/LaPresse)

A demonstrator holds up a picture depicting Russian President Vladimir Putin with make-up, during a protest by the gay community in Amsterdam April 8, 2013. Russia does not discriminate against homosexuals, Putin told reporters in Amsterdam on Monday where he was greeted by gay rights and other activists critical of Russia's track record. Putin is on one-day visit in the Netherlands for the start of the Netherlands-Russia Year. (Photo by Cris Toala Olivares/Reuters)

In this Thursday, April 11, 2013 photo, an Afghan woman peers through the the eye slit of her burqa as she waits to try on a new burqa in shop in the old town of Kabul, Afghanistan. (Photo by Anja Niedringhaus/AP Photo)

Maria, 18, wearing a traditional Sevillana outfit, poses for a portrait during the traditional Feria de Abril (April fair) in the Andalusian capital of Seville April 16, 2013. (Photo by Marcelo del Pozo/Reuters)