Yueyaquan is a crescent-shaped lake in an oasis, 6 km south of the city of Dunhuang in Gansu Province, China. It was named Yueyaquan in the Qing Dynasty. According to measurements made in 1960, the average depth of the lake was 4 to 5 meters, with a maximum depth of 7.5 metres In the following 40 years, the depth of the lake continually declined. In the early 1990s, its area had shrunk to only 5,500 m2 with an average depth of 0.9 meter (maximum 1.3 meter). In 2006, the local government with help of the central government started to fill the lake and restore its depth; its depth and size have been growing yearly since then. The lake and the surrounding deserts are very popular with tourists, who are offered camel and 4x4 rides.

Kashmiri vegetable vendors assemble at a floating market in the interiors of the Dal Lake in Srinagar April 17, 2012. (Photo by Danish Ismail/Reuters)

A hyena eyes a herd of zebra at Lake Nakuru National Park, Kenya, August 19, 2015. The Park is home to some of the world's most majestic wildlife including lions, rhinos, zebras and flamingos. The scenery is stunning, from forests of acacia trees to animals congregating at the shores to drink. UNESCO says that with rapid population growth nearby, the area is under "considerable threat from surrounding pressures," particularly deforestation, a contributing factor in floods. (Photo by Joe Penney/Reuters)

The Komodo National Park is a national park in Indonesia located within the Lesser Sunda Islands in the border region between the provinces of East Nusa Tenggara and West Nusa Tenggara. The park includes the three larger islands Komodo, Padar and Rinca, and 26 smaller ones, with a total area of 1,733 km² (603 km² of it land). The national park was founded in 1980 to protect the Komodo dragon, the world's largest lizard. Later it was dedicated to protecting other species, including marine species. In 1991 the national park was declared a UNESCO World Heritage Site and later as Man and Biosphere Reserve.

Glacier National Park is a national park located in the U.S. state of Montana, on the Canada–United States border with the Canadian provinces of Alberta and British Columbia. The park encompasses over 1,000,000 acres (4,000 km2) and includes parts of two mountain ranges (sub-ranges of the Rocky Mountains), over 130 named lakes, more than 1,000 different species of plants and hundreds of species of animals. This vast pristine ecosystem is the centerpiece of what has been referred to as the "Crown of the Continent Ecosystem", a region of protected land encompassing 16,000 square miles (41,000 km2).

A model of a prehistoric icthyosaurus is dragged from its pond in the grounds of Crystal Palace, London, for its annual clean. The 'keeper' is being helped by some of the local police force. (Photo by Fox Photos/Getty Images). February 1927

A participant takes part in the Bristol Park and Slide project, an interactive temporary installation by artist Luke Jerram set up in Park Street in the centre of Bristol, southwest England on May 4, 2014. Over 95,000 people applied for just 360 tickets to slide on inflatable lilos down a lubricated water slide in a town centre street. (Photo by Leon Neal/AFP Photo)