Type: Cenote ( deep natural pit)
Location: Ik-Kil , Mexico
Depth: 85 feet
Brief description/events highlight, etc: The cenote is open to the sky and there are vines which reach from the opening all the way down to the water along with small waterfalls. There are black catfish which swim in the cenote.



Type: Sinkhole
Location: Neversink Pit, Alabama
Depth: 50 feet
Brief description/events highlight, etc: Wet limestone sinkhole in Alabama seen above in 1998 and houses a rare species of fern. The sinkhole was bought in the 1990s by a group of cavers to preserve it for future generations.

Type: Sinkhole
Location: El Zacatón
Depth: 1,112 feet
Brief description/events highlight, etc: It is known as the deepest water-filled sinkhole in the world. It was long considered to be bottomless, but in 1997 NASA solved the pit’s mystery when they sent an underwater robot into El Zacaton and found the depth is actually 1,112 feet.



Type: Sinkhole
Location: Daisetta, Texas
Depth: 206 feet
Brief description/events highlight, etc: The sinkhole opened on May 7, 2008. The former oil town sits on the Hull Salt Dome which is a four-mile-in-diameter geologic formation of compacted salt. Geologists speculate that years of storing byproduct water waste caused the massive sinkhole.



Type: Sinkhole
Location: Berezniki, Russia
Depth: 650 feet
Brief description/events highlight, etc: This sinkhole first opened up in 1986 when a nearby potash mine flooded and began collapsing. Several papers have been written on the causes of the sinkhole. It now threatens to swallow the only rail line and support buildings in the area. This hole may not be the biggest or deepest, but is globally important because 10% of the world output of potash comes from this area, and the sinkhole threatens production from this critical source.



Type: Sinkhole
Location: Charlotte Motor Speedway infield
Depth: 35 feet
Brief description/events highlight, etc: It was formed in the field of the Charlotte Motor Speedway on September 2010 when a 30-year-old drain pipe deteriorated. Official said that the speedway was built on top of an old landfill, and heavy rains contributed to the underground collapse.



Type: Sinkhole
Location: Devil’s Den, Williston, Florida
Depth: 68 feet
Brief description/events highlight, etc: Devil’s Den is a fern-draped sinkhole created by several underground springs found in Williston, Florida. The water averages 22 degrees Celcius (72 Fahrenheit), and on cold winter mornings, steam can be seen rising from the ground. Early settlers named it the pit Devil’s Den.