Earth is composed of a vast surface. According to scientists and researchers, it's total surface is 510 million square kilometers (about 197 million square miles). Around 70.8% of the surface is covered by ocean water and the remaining 29.2% is a terrain of mountains, deserts, plains and other landforms.
According to studies, humans have "discovered" the entire land surface of Earth with the help of satellites that's orbiting around the Earth, but some of it remains "unexplored" like jungles, deserts, and other cold areas. But not many people know that only 5% of the ocean floor is discovered and the remaining 95% remains unexplored. In fact, just recently another discovery on the ocean abyss was revealed.
According to International Business Times UK, divers confirmed that the world's deepest underwater cave as of to date can be found in the Czech Republic. The cave is called "Hranická Propast" and it is 1,325 feet (404 meters) deep into the entrails of Earth. They began to explore the cave way back in 1999 but it is only now that they are able to measure its depth.
The report also says that over the decades, divers would usually visit the cave every now and then and just last year, they found a passage in the cave that can be easily penetrated by a remotely operated underwater vehicle (ROV) to have it explored. On September 27, divers were able to guide the ROV to the record-breaking depth of 1,325 feet.
In a separate report by Live Science, once the divers were able to explore the depth of the cave, they were able to discover fallen trees, logs, and branches at the bottom. The discovery suggests that the cave had "changed its shape," according to divers. They are also surprised that the cave is large as supposed to what they first thought.
Marcin Jamkowski, a member of the expedition team, noted that they will still continue to explore and study the cave for they believe that they can still go down deep in it.