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.

Fishermen jump into a small river to catch trout as they celebrate Fischertag (Fisherman's Day) in downtown Memmingen, southern Germany, July 25, 2015. The annual Fisherman's Day (Fischertag) tradition goes back to the year of 1465 where every fisherman who were born in Memmingen tries to catch trout from the river. The participant who catches the biggest trout will be named the “Fisher King” for one year. (Photo by Michaela Rehle/Reuters)

In one of the planet’s most desolate and harsh terrains, the Altai Mountains which run from Siberia in Russia down to Mongolia’s Gobi Desert, hunting with eagles is currently only practiced by a handful of Kyrgyz and Kazakhs. This form of falconry, the practice of hunting with the aid of birds of prey, can be traced back as far as 4,000 years in Central Asia. Here: after a successful hunt, a proud hunter rewards his eagle by feeding it the lungs of the prey, which is considered the most highly prized part of the animal. (Photo by Tariq Zaidi/The Washington Post)

Ultra Orthodox Jews look at the body of an alleged Palestinian assailant in Jerusalem Saturday, December 26, 2015. According to a police spokeswoman, policemen approached a man who drew their suspicions just outside the Old City for following a pair of Jewish worshippers. Then he pulled out a knife and tried to stab one of them, officers opened fire and killed the assailant. (Photo by Mahmoud Illean/AP Photo)

Neil Zeller's snaps were taken across Canada, where he photographs the northern lights dancing across a dark night sky. In one stunning shot, Zeller, 42, even manages to capture a flash of lightning beneath a storm cell while an aurora gives off a magnificent green glow. The photographer, from Calgary, Alberta, describes himself as a night person, and became interested in night photography about 10 years ago. (Photo by Neil Zeller/Caters News)

Volunteers try to keep alive some of the hundreds of stranded pilot whales after one of the country's largest recorded mass whale strandings, in Golden Bay, at the top of New Zealand's south island, February 10, 2017. Volunteers in New Zealand managed to refloat about 100 surviving pilot whales on Saturday, February 11, 2017 and are hoping they will swim back out to sea after more than 400 of the creatures swam aground at a remote beach. (Photo by Ross Wearing/Reuters)

A “Federahannes”, a jester figure from Rottweil, participates in the “Narrensprung” (jester jump) parade in Rottweil, southern Germany, Monday, February 27, 2016. About 4000 jesters paraded through the city among thousands of spectators. The Rottweil Narrensprung is the highlight of the Swabian-Alemannic Fastnacht and one of the traditional pre-Lenten carnival parades in southwestern Germany. (Photo by Michael Probst/AP Photo)

One of four Acehnese teen gets whipped for spending time in close proximity with her boyfriend who is not her husband, which is against Sharia law, in Aceh on April 18, 2017. Aceh on Sumatra island began implementing Sharia law after being granted special autonomy in 2001, an attempt by the central government in Jakarta to quell a long-running separatist insurgency. (Photo by Chaideer Mahyuddin/AFP Photo)