THIS is interesting.
The world's deepest underwater cave has been discovered by a team of explorers in the Czech Republic, measuring at least 404 metres (1,325 feet) deep.
The flooded limestone sinkhole, known as the Hranicka Propast or Hranice Abyss, is located in the Hurka u Hranic nature reserve in the country's east.
It has been surveyed numerous times by Polish explorer Krzysztof Starnawski over the last 20 years, but Mr Starnawski had never, until now, been able to measure beyond a depth of 370 metres (1,214).
This time, during the expedition carried out on September 27, the team employed the help of a remotely-operated underwater robot (ROV) to explore the deeper, narrower depths of the abyss.
But the robot was still unable to find the bottom as it reached the end of its cord at 404 metres, suggesting the cave may actually extend much further down.
It was, however, more than enough to beat the previous record holder, the Pozzo del Merro sinkhole in Italy, by 12 metres.
The expedition was funded in part by National Geographic.