Jacob's Well is a perennial karstic spring in the Texas Hill Country flowing from the bed of Cypress Creek, located northwest of Wimberley, Texas. The twelve foot (four meter) diameter mouth of the spring serves as a popular swimming spot for the local land owners whose properties adjoin Cypress Creek. From the opening in the creek bed, Jacob's Well cave descends vertically for about thirty feet (ten meters), then continues downward at an angle through a series of silted chambers separated by narrow restrictions, finally reaching a depth of one hundred and twenty feet (forty meters). Until the modern era, the Trinity Aquifer-fed natural artesian spring gushed water from the mouth of the cave, with a measured flow in 1924 of one hundred and seventy gallons per second (six hundred and forty liters per second) discharging six feet (two meters) into the air. The spring is the greatest source of water recharging the Edwards Aquifer.

Pictures from Tasmania’s central plateau, shot by wilderness photographer Dan Broun, show the extraordinary damage wrought by more than a week of bushfires following lightning strikes in Australia’s southernmost state on January 13. 2016. The world heritage area was home to a range of unique alpine flora including pencil pines, king billy pines and cushion plants, some more than 1,000 years old. Now more than 10,000ha of land has been incinerated, and ecologist say that, unlike eucalyptus trees, the ancient flora will not recover. (Photo by Dan Broun)

Students from Langata primary school run past riot police as they protest against a perimeter wall illegally erected by a private developer around their school playground in Kenya's capital Nairobi January 19, 2015. Riot police used teargas to disperse students at a school in Nairobi as the children protested against the potential loss of their playground. The playground was fenced off in December, during the school holidays, by a prominent developer who also claims ownership of the land. The title to the contested site is said to be in the name of Airport View Housing Limited, according to local media, with plans to use the space to build a parking lot for a hotel. (Photo by Thomas Mukoya/Reuters)

These chilling images prove there is no sign of life at this abandoned tuberculosis treatment hospital. Johnny Joo, 24, captured the eerie shots of the desolate TB ward, in Perrysburg, New York. Where equipment lies gathering rust and walls are left crumbling. The photojournalist, from Cleveland, Ohio, stumbled upon the facility, which shut its doors in 1995, before shooting what remains of the historic site. Johnny said the facility, named after Buffalo Mayor James Nobel Adam, remains something of an unknown quantity as it is surrounded by more than 500 acres of forest land. (Photo by Johnny Joo/Caters News)

“The Yao nationality is a government classification for various minorities in China. They form one of the 55 ethnic minority groups officially recognized by the People's Republic of China, where they reside in the mountainous terrain of the southwest and south”. – Wikipedia

Photo: A woman combs her hair at the Huangluo Village of the Yao ethnic group in Guilin, south China's Guangxi Zhuang Autonomous Region, July 15, 2012. The Huangluo Village of the Yao ethnic group locates at the Longji Terraces in Heping Town of Longsheng County in Guilin. Women here have the tradition of keeping long hair. They believe that long hair brings good luck and fortune. The average length of hair of 180 women in the village is 1.7 meters. (Photo by Lu Boan/Xinhua)

PUMA Ocean Racing powered by BERG, skippered by Ken Read from the USA, sails past the Guan Yin of the South Sea of Sanya, at the start of leg 4 of the Volvo Ocean Race 2011-12 on February 19, 2012 from Sanya, China to Auckland, New Zealand. (Photo by Paul ToddVolvo Ocean Race via Getty Images)

A rescue helicopter is shown at the Mount Everest south base camp in Nepal a day after a huge earthquake-caused avalanche killed at least 17 people, in this photo courtesy of 6summitschallenge.com taken on April 26, 2015 and released on April 27, 2015. Rescue teams, helped by clear weather, used helicopters to airlift scores of people stranded at higher altitudes, two at a time. (Photo by Reuters/6summitschallenge.com)

Party-goers partake in a festival better known as Holi One, during International Workers Day in Johannesburg, South Africa, 01 May 2015. The colour festival promotes togetherness as well as colourness in everday life. May Day is observed worldwide every year on 01 May. (Photo by Kevin Sutherland/EPA)