Salar de Uyuni (or Salar de Tunupa) is the world's largest salt flat at 10,582 square kilometers (4,086 sq mi). It is located in the Potosí and Oruro departments in southwest Bolivia, near the crest of the Andes, and is elevated 3,656 meters (11,995 ft) above mean sea level. The Salar was formed as a result of transformations between several prehistoric lakes. It is covered by a few meters of salt crust, which has an extraordinary flatness with the average altitude variations within one meter over the entire area of the Salar.

Aerial view of a giant sinkhole on June 09, 2021 in Santa María Zacatepec, Mexico. The giant sinkhole is located 20 kilometers northwest from the capital city Puebla, the hole now measures 110 meters across its widest point, covering around 11,000 square meters and damaging a house built near the place where it appeared. Farmers of the surroundings have been affected since they are not allowed to enter their fields due to the warning perimeter set up by the authorities. (Photo by Hector Vivas/Getty Images)

A woman plays around as she walks across a glass-bottomed suspension bridge in a scenic zone in Pingjiang county in southern China's Hunan province Thursday, September 24, 2015. The bridge, 300 meters (984 feet) long and 180 meters (590 feet), opened to visitors on Thursday for the first time since its conversion from a regular suspension bridge was completed. (Photo by Chinatopix Via AP Photo)

Turkish National athlete Sahika Ercumen persists in her preparations for the dive along the shores of Karamagara Bay as she will dive to break the 105-meter world record in the variable weight category without fins on the 100th anniversary of the Turkish Republic in Hatay, Turkiye on October 15, 2023. The national athlete is determined to exceed the 105-meter world record currently held by Serbian diver Lena Balta in the variable weight category without fins. (Photo by Sebnem Coskun/Anadolu via Getty Images)

A 69-meter-tall giant Buddha statue stands at the Wat Paknam Phasi Charoen temple on the outskirts of Bangkok on October 12, 2021. (Photo by Jack Taylor/AFP Photo)

Leilani Franco has made it into the Guinness Book of World Records for the fastest human backbend walk, traveling in a backbend position a distance of 20 meters (65 ft 7.2 in) in a time of 10.05 seconds. (Photo by PA Wire)

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)

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.