Best Natural Sinkhole

Sima Martel, also known as the Martel Pit, is a substantial sandstone sinkhole located within the Sarisarinama Tepui in Venezuela. This unique geological feature represents one of the largest tepui-sinkholes globally. Its extreme isolation has fostered a distinct ecosystem supporting endemic plant a...

Red Lake (Crveno Jezero) is a deep sinkhole in Croatia formed by karst processes. Its notable depth, exceeding 245 meters, makes it one of Europe’s deepest known sinkholes. The distinctive red cliffs are due to mineral-rich water depositing over time. Geologists and researchers studying karst format...

Blue Lake, known in Croatian as Modro Jezero, is a karst lake in a deep sinkhole beside the town of Imotski in Croatia. Its water level varies substantially with rainfall, groundwater conditions, and the season, changing the lake's depth and accessible shoreline. In exceptionally dry periods it can...

Cenote Maravilla is a deep, partially collapsed sinkhole in Mexico's Yucatan state, notable for its spectacular sunbeams that pierce through the surface opening.

Cenote Saamal is a large, open-air sinkhole located in Mexico's Yucatan Peninsula, situated within the Hacienda Selva Maya eco-park. It is distinguished by a waterfall that cascades from above into the natural pool below. Cenotes are natural sinkholes formed by the collapse of limestone bedrock, exp...

The Hranice Abyss is a flooded karst sinkhole situated in the Moravia region of the Czech Republic. It is recognized as the deepest known flooded freshwater cave globally, with robotic surveys confirming a depth exceeding 404 meters. The water is naturally warm and heavily mineralized, which has his...

Jacob's Well is a perennial artesian spring located near Wimberley, Texas, issuing from a submerged karst cave system. The primary shaft descends vertically for several meters before branching into a network of extensive underwater passages, making it one of the longest underwater cave systems in Te...

Pozzo del Merro is a water filled sinkhole in the Monti Cornicolani area northeast of Rome, Italy. Remotely operated underwater surveys have reached a depth of about 392 meters without identifying the bottom, making it one of the deepest explored flooded karst features on land. Its steep submerged s...

Ginnie Springs is a cluster of natural freshwater springs located in Gilchrist County, Florida, along the banks of the Santa Fe River. The privately owned park features seven distinct springs that pump millions of gallons of crystal-clear water daily, making it a highly visited destination for swimm...

Bimmah Sinkhole (Hawiyat Najm) is a coastal sinkhole in northeastern Oman, roughly 40 m across, where freshwater and seawater mix and which is managed as a public park.

A Florida State Park in Columbia County containing the Peacock Springs cave system, one of the longest surveyed underwater cave systems in the United States.

A large natural sinkhole in Edwards County, Texas, about 15 meters wide and 50 meters deep, serving as a roosting site for millions of Mexican free-tailed bats.

Cenote Yokdzonot is a community-managed open cenote in Yucatán, Mexico, operated by a local cooperative since the early 2000s as a model of small-scale sustainable ecotourism.

A geological sinkhole near Gainesville, Florida, approximately 36 meters deep and 120 meters wide, preserved as Devil's Millhopper Geological State Park.

A commercial spring and dive facility in Holmes County, Florida, featuring an underwater cave system and one of the state's most accessible cave-diving training sites.