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)

Shooting star by Tony Wu, US/Japan. Winner, underwater. The electrifying reproductive dance of a giant sea star. As the surrounding water filled with sperm and eggs from spawning sea stars, Wu faced several challenges. Stuck in a small, enclosed bay with only a macro lens for photographing small subjects, he backed up to squeeze the undulating sea star into his field of view. The dancing posture of spawning sea stars rising and swaying may help release eggs and sperm, or may help sweep the eggs and sperm into the currents where they fertilise together in the water. Kinko Bay, Japan. (Photo by Tony Wu/Wildlife Photographer of the Year)

Though schools around the globe have different start dates, calendars and traditions, the first day of a new term is an exciting time filled with the prospects of gaining more knowledge, making new friends and building community. Here: Schoolchildren attend their first lesson on Knowledge Day in the town of Turov, Zhytkavichy District, Gomel Region, Belarus on September 1, 2017. Knowledge Day marks the beginning of a new school year in Belarus and is celebrated on September 1. (Photo by Viktor Drachev/TASS via Getty Images)

In this March 21, 2015 photo, 15-year-old Guerline Augustin carries river water on her head, back to a borderland encampment outside the southeast Haitian town of Anse-a-Pitres, Haiti. The encampment is filled with people who either fled or were forcibly removed from the neighboring Dominican Republic amid an immigration crackdown. Within the next month, authorities hope to move nearly 2,400 people out of six encampments by providing subsidies for them to rent homes for a year in southeastern Haiti. The International Organization for Migration is coordinating the effort with $2 million from a U.N. emergency fund. (Photo by David McFadden/AP Photo)

Kevin Russ, a photographer & image moderator for iStockphoto, grew up in Arroyo Grande, California. In 2003, he made the move to Portland, planning to study at Multnomah Bible College. Finding the workload to be minimal, Kevin invested in a camera, filling his free time and finding himself instantly smitten with the craft. A year and a half later, photography had evolved into his full-time job. However, after 4 years of consistent portrait work, Kevin became burnt out and took a step back from photography altogether. Two years later, he picked up the camera again and now spends the majority of his time on the road, exploring & photographing the rustic landscapes & wildlife he encounters.

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.

A woman jumps into water from the roof of Murru prison, an abandoned Soviet prison, in Rummu quarry, Estonia, during hot weather July 4, 2015. During the Soviet time, Rummu quarry was used as a mining site for Vasalemma marble and most of the workforce came from among the detainees of Murru prison. When the prison closed after 1991, pumps that once kept the quarry and the prison dry were shut down, causing water to fill the quarry. It has become an unofficial and unguarded swimming and diving spot, attracting locals and tourists. (Photo by Ints Kalnins/Reuters)