Surfers surf at Surf Snowdonia in Conwy, North Wales, September 3, 2015. The surf park, which cost $22.8 million, opened on August 1 and is the world's first commercial artificial surfing lake, according to the company.The pool is 300 metres (980 ft) long and 110 metres (360 ft) wide, containing a total of six million gallons of water. A bi-directional snowplough-shaped wave-generation mechanism, towed on a cable between the two central towers, moves up and down the pool on a three-rail track, generating the waves. (Photo by Andrew Yates/Reuters)

Participant rides a carousel at the women's-only Petrolettes motorcycle festival on July 21, 2018 in Milmersdorf, near Berlin in Germany. Around 300 bike women from across Europe come together for the third edition of the festival. Women connect their passion for high speed motorbikes with music, movies, races, yoga etc. Festival that goes for three days was initiated by a group of female motorbike riders called The Curves. (Photo by Maja Hitij/Getty Images)

A visitor poses inside a three story upside-down family sized house at the Huashan Creative Park in Taipei, Taiwan April 7, 2016. Over 300 square meters of floor space of the upside-down house, filled with home furnishings, was created by a group of Taiwanese architects at a total cost of around US$600,000 and took 2 months to complete, according to the organisers. (Photo by Tyrone Siu/Reuters)

A woman takes a photo on her mobile phone of a tiger during the media preview of Vivid Sydney at Taronga Zoo on May 19, 2019 in Sydney, Australia. An illuminated trail of almost 300 lit lanterns of endangered species will glow every night at the zoo during Vivid Sydney which runs from May 24 throughout Sydney with hundreds of lit buildings and exhibits which attract hundreds of thousands of visitors each year. (Photo by James D. Morgan/Getty Images)

In this photo taken Wednesday, April 30, 2014, a dragonfly sits on the nose of a Gharial, rare crocodile-like creatures, in the River Chambal near Bhopepura village in the northern Indian state of Uttar Pradesh. The narrow 250-mile stretch of the Chambal is a place of crocodiles and jackals, of river dolphins and the occasional wolf. Hundreds of species of birds, storks, geese, babblers, larks, falcons and so many more, nest along the river. Endangered birds lay small speckled eggs in tiny pits they dig in the sandbars. Gharials, rare crocodile-like creatures that look like they swaggered out of the Mesozoic Era, are commonplace here and nowhere else. (Photo by Altaf Qadri/AP Photo)

Ng Sin Nee (L) and Lee Shin May (R) from Malaysia take pictures with the panoramic view of the city from the Sky Box at KL Tower, the world's seventh tallest telecommunications tower, in Kuala Lumpur on May 24, 2016. Officially opened on May 20, the Sky Box has been the latest attraction for tourists arriving to the Malaysian capital. It stands 300 metres above ground and can fit six people at any one time, and offers spectacular views of the Kuala Lumpur skyline, including the iconic Petronas Twin Towers. (Photo by Mohd Rasfan/AFP Photo)

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.