A lady smiles during the annual Calabar cultural festival in Calabar, Nigeria, December 28, 2015. Picture taken December 28, 2015. (Photo by Reuters/Stringer)
A boy carries sugar cane through a farm on the outskirt of Zaria in Nigeria's northern state of Kaduna November 15, 2016. (Photo by Akintunde Akinleye/Reuters)
A young boy scavenges for re-sellable items from garbage on the streets, runs past a sign showing incumbent President Muhammadu Buhari, left, and local party official Mustapha Dankadai, right, in Kano, northern Nigeria Friday, February 15, 2019. (Photo by Ben Curtis/AP Photo)
8-year-old Fulani boy Suleiman Yusuf drinks milk from a cow belonging to his father cattle near his family's house at Kachia Grazing Reserve, Kaduna State, Nigeria, on April 16, 2019. Kachia Grazing Reserve is an area set aside for the use of Fulani pastoralist and it is intended to be the foci of livestock development. The purpose for the grazing reserves is the settlement of nomadic pastoralists and inducement to sedentarisation through the provision of land for grazing and permanent water as way to avoid conflict. (Photo by Luis Tato/AFP Photo)
Children stand in a boat at the banks of the polluted Yamuna River during a dust haze as they wait to give a ride to worshippers in New Delhi during World Environment Day June 5, 2010. (Photo by Reinhard Krause/Reuters)
Tourist Michel Watson found this pink dolphin making a splash in Brazil. The unusual creature, which hides deep in the Rio Negro river, was spotted leaping out of the Amazonian water brandishing its bizarre bright bubblegum color. Weighing in at nearly 300 pounds, the curious animal, known as an Amazon Pink River Dolphin, looked unusually agile as it rose above the waves. (Photo by Michel Watson)
The Puerto Princesa Subterranean River National Park is located about 50 kilometres (30 mi) north of the city centre of Puerto Princesa, Palawan, Philippines. The river is also called Puerto Princesa Underground River. The national park is located in the Saint Paul Mountain Range on the northern coast of the island. It is bordered by St. Paul Bay to the north and the Babuyan River to the east. The City Government of Puerto Princesa has managed the National Park since 1992. The park is also known as St. Paul's Subterranean River National Park, or St. Paul Underground River. The entrance to the Subterranean River is a short hike from the town of Sabang.
The Verzasca is a Swiss 30-km long mountain river originating at Pizzo Barone and flowing into Lake Maggiore. It is known for its clear turquoise water and vibrant colored rocks, as well as its treacherous currents. The Verzasca Dam is a few kilometers upriver from this lake.