The Hranice Abyss — or "Hranická propast," in Czech — is the deepest known freshwater cave in the world. Geologists think it could extend more than half a mile (1 kilometer) below Earth's ...

Explorers researching the world's deepest freshwater cave are still working to get to the bottom. The Hranice Abyss in Moravia, Czechia, is deeper than once thought after a team of researchers ...

Freshwater pufferfish ... and sea urchins. They then rest in caves or crevices at night Spiky pufferfish prefer a nocturnal schedule. They hunt at night, using the hard plates in their mouth ...

Nearly 90 freshwater species have already been reported extinct, Sayer said. Of the threatened species, 54% of studied species are thought to be affected by pollution. Woodville Karst Cave ...

The canoe was discovered in an underwater cave in 2021. National Institute of Anthropology and History A well-preserved Maya canoe found in a Mexican freshwater cave may have been placed there as ...

The body of a diver who sank without a trace during a risky dive was left at the bottom of an 800-foot underwater hole for 10 years until a chance discovery led to efforts to retrieve his body.

Why it's incredible: The cave is so deep, the world's tallest building could fit inside it. The Hranice Abyss — or "Hranická propast," in Czech — is the deepest known freshwater cave in the ...