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 visitor jumps for a photograph on the world's highest and longest glass-bottomed bridge above a valley in Zhangjiajie in China's Hunan Province on August 21, 2016. The bridge, which opened to the public on a trial basis on Saturday, spans 430 meters (1,410 feet) and rises about 300 meters (984 feet) above a valley in a scenic zone, making it the world's highest and longest glass-bottomed bridge according to Chinese state media. (Photo by Fred Dufour/AFP Photo)

Aerial view of Christ The Protector Statue at sunrise on April 21, 2021 in Encantado, Brazil. The statue under construction in Encantado, Southern Brazil, will be named Cristo the Protector and will surpass the iconic Christ The Redeemer of Rio de Janeiro by five meters. Made of steel and concrete, it will stand 43 meters including its pedestal, and become the third-tallest statue of Jesus Christ in the world. (Photo by Buda Mendes/Getty Images)

A view of the world's highest 280-meter bungee jumping platform opened at the Milad Tower, a landmark in the Iranian capital Tehran, on September 11, 2024. The world's highest bungee jumping platform attracts great interest among the younger generation in Iran, especially women. Those who jump from the platform experience an unforgettable adventure with the thrill of soaring down from a height of 280 meters while watching the view of Tehran from above. (Photo by Fatemeh Bahrami/Anadolu via Getty Images)

Moscow’s Red Square has seen its share of strange stuff over the centuries, from medieval public executions to artistic self-mutilations. But a giant Louis Vuitton suitcase took many Muscovites completely by surprise. The 9-meter high, 30-meter long building covered in iconic gold-on-brown pattern erected last week is to host a historic exhibition.

Tom Palmer, the England lock, dives off at the 134 meter high Nevis Bungy jump during an England IRB Rugby World Cup 2011 team visit on September 12, 2011 in Queenstown, New Zealand. (Photo by David Rogers/Getty Images)

Visitors of the world's longest tree top walk between the trees of the Bavarian forest on November 6, 2009 in Neuschoenau, Germany. The path, 1300 meters long and in 8 to 25m height, winds up to an impressive tower with a height of 44 meters. The wooden construction is integrated into the forest and delivers a natural experience. (Photo by Miguel Villagran/Getty Images)

Jaheel Hyde, of Jamaica, competes in a men's 400-meter hurdles heat at the 2024 Summer Olympics, Monday, August 5, 2024, in Saint-Denis, France. (Photo by David J. Phillip/AP Photo)