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.

Breitling Wingwalker Freya Paterson, from Liverpool, UK, flies above Kuwait City's iconic Water Towers with pilots David Barrell and Martyn Carrington, on March 6, 2014. The team loop and roll up to 160 mph enduring G-forces of 4-5g. Crowds are expected to line the Kuwaiti coastline to catch a glimpse of the Wingwalking team on Saturday, March 8, 2014, to mark the opening of the first dedicated boutique in the city for the prestigious watch brand. (Photo by Katsuhiko Tokunaga/Breitling)

An Indian Sikh devotee takes a dip in the holy sarover (water tank) at the Golden Temple on the eve of “Ghallughara Diwas”, the 29th Anniversary of Operation Bluestar, in Amritsar on June 5, 2013. The 1984 assault on the Golden Temple complex by the Indian army was conducted in an attempt to arrest separatists Sikh leader Sant Jarnail Singh Bhindranwale and his militant followers who had initiated a movement for a separate Sikh state. (Photo by Narinder Nanu/AFP Photo)

These are incredible pictures of skilled aircraft pilots flying through raging infernos to put out enormous flames. Daredevil Italian photographer Antonio Grambone, 46, jumped up close to the blaze to capture the incredible images of forest fires in the National Park of Cilento and Vallo di Diano, in the province of Salerno in Italy. At great risk to himself, Antonio captured these incredible shots making them appear like Italian masterpieces.

Photo: On target: Brave pilots are on a course straight into these enormous flames as they release tonnes of water onto the fire. (Photo by Antonio Grambone/Caters News Agency Ltd)

A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, May 22, 2015. In Sudan, which faces insurgences in the western region of Darfur and along its border with breakaway South Sudan, as well as double-digit inflation and high unemployment, life goes on for young people in the capital Khartoum. (Photo by Mohamed Nureldin Abdallah/Reuters)

Farmworkers clear weeds in a strawberry field at a farm in Huaral on the outskirts of Lima, Peru, August 5, 2015. Farmers in northern Lima use pressurized irrigation and plastic wraps for efficient production of strawberries in a coastal area with little water, according to local media. (Photo by Mariana Bazo/Reuters)

Revelers celebrate the Indian festival of Holi on the deck of the ship Peking at South Street Seaport in Manhattan March 19, 2011 in New York City. The Hindu festival of Holi , also known as the Festival of Colors, marks the arrival of spring where participants throw colored powder and water on one another. Many of the New York participants are Indian-American.

Odin, a five year-old White Bengal Tiger dives for a piece of meat thrown to him by a trainer during a big cat show at Six Flags Discovery Kingdom June 1, 2007 in Vallejo, California. Unlike most cats that are afraid of water, Odin loves diving in the pool to retrieve bits of meat fed to him by his trainers. (Photo by Justin Sullivan/Getty Images)