Pozzo del Merro is a flooded
sinkhole in the countryside northeast of
Rome,
Italy. Situated at the bottom of an 80 m conical pit, at it is the second deepest underwater
vertical cave in the world. In 2000 two
ROVs
The Russian All-Military Union ( rus, Русский Обще-Воинский Союз, abbreviated РОВС, ROVS) is an organization that was founded by White movement, White Army General Pyotr Wrangel in the Kingdom of Serbs, Croats and Slovene ...
were sent to explore its depths; the first, the "Mercurio (Mercury)" reached its maximum operative depth of without reaching the bottom. The second ROV, "Hyball 300", reached without touching down either.
A third dive in 2002 with the more advanced "Prometeo" robot reached the bottom at , but discovered a narrow passage continuing horizontally.
The sinkhole, similar to the
Zacatón cenote, was formed by volcanic activity eroding the
carbonate rock.
References
Sinkholes of Italy
Metropolitan City of Rome Capital
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