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.

A giant size figure of the United States' goalkeeper Tim Howard is displayed outside a shopping mall in Hong Kong, Thursday, June 12, 2014, to promote the upcoming 2014 World Cup in Brazil. A total of seven 3.5 meters to 4 meters (11 feet 6 inch to 13 feet one inch) tall figures of famous players attract many soccer fans. (Photo by Vincent Yu/AP Photo)

Inês Carvalho (C), accompanied by her sister and cousin, is helped by her aunt to dress up at Alfama neighborhood in Lisbon on June 12, 2014. Carvalho, 18, is one of the revelers from the Alfama march and every Saint Anthony's day, Lisbon's protector, she parades with several other typical neighborhoods of the city. (Photo by Patricia De Melo Moreira/AFP Photo)

Travellers ride their horse through the river during the Appleby Horse Fair on June 5, 2014 in Appleby, England. The Appleby Horse Fair has existed under the protection of a charter granted by James II since 1685 and is one of the key gathering points for the Romany, gypsy and traveling community. The fair is attended by about 5,000 travellers who come to buy and sell horses. The animals are washed and groomed before being ridden at high speed along the “mad mile” for the viewing of potential buyers. (Photo by Nigel Roddis/Getty Images)

A boat, center, is surrounded by Japan Cost Guard's patrol boats after some activists descended from the boat on Uotsuri Island, one of the islands of Senkaku in Japanese and Diaoyu in Chinese, in East China Sea Wednesday, Aug. 15, 2012. Regional tensions flared on the emotional anniversary of Japan's World War II surrender as activists from China and South Korea used Wednesday's occasion to press rival territorial claims, prompting 14 arrests by Japanese authorities. The 14 people had traveled by boat from Hong Kong to the disputed islands controlled by Japan but also claimed by China and Taiwan. (Photo by Yomiuri Shimbun/Masataka Morita/AP Photo)

Japanese women wearing “yukata” casual summer kimono take selfies at Asakusa district in Tokyo, Japan, 13 September 2020. Asakusa is one of Tokyo's most-visited areas and is usually crowded with tourists. In Japan, the numbers of visitors from abroad fell by 99.9 percent from a year earlier in July due to the ban for entries of foreign visitors amid the coronavirus pandemic. (Photo by Franck Robichon/EPA/EFE)

Bar Convent employee Lauren Masterman relaxes after cleaning a historic George and Arthur Maw tiled floor created in 1867, one of only two surviving examples of this assemblage of tiles, at England's oldest living convent Bar Convent on October 13, 2020. Visitors to the convent are being invited to follow in the footsteps of residents from the last 150 years and enjoy the historic space decorated with rare 19th century floor tiles. (Photo by Danny Lawson/PA Images via Getty Images)

Anthony Joshua punches Kubrat Pulev during the IBF, WBA, WBO and IBO World Heayweight Title fight between Anthony Joshua and Kubrat Pulev at The SSE Arena, Wembley on December 12, 2020 in London, England. A limited number of fans (1000) are welcomed back to sporting venues to watch elite sport across England. This was following easing of restrictions on spectators in tiers one and two areas only. (Photo by Andrew Couldridge – Pool/Getty Images)