Sinkhole divers. Some of the most spectacular are the Zacatón cenote in Mexico (the world's deepest water-filled sinkhole), the Boesmansgat sinkhole in South Africa, Sarisariñama tepuy in Venezuela, the Sótano del Barro in Mexico, and in the town of Mount Gambier, South Australia. Sinkholes that form in coral reefs and islands that collapse to enormous depths are known as blue holes and often become popular diving spots. Large and visually unusual sinkholes have been well-known to local people since ancient times. Nowadays sinkholes are grouped and named in site-specific or generic names. Some examples of such names are listed below. The
Egma Sinkhole Egma Sinkhole EGMA Sinkhole (), a.k.a. Peynirlikönü Sinkhole, is a sinkhole and the deepest cave in Turkey. It is located at Sugözü village of Anamur, Mersin. The sinkhole is deep and long. EGMA stands for Evren Günay - Mehmet Ali Özel Sinkhole. Beginning in 1993, the cave was being explored by BÜMAK (Boğaziçi University Speleological Society). A flash flood caused Mehmet Ali Özel to lose his life inside the cave in 2001. In 2004, with the help of members of the Bulgarian Speleological Federation, the BÜMAK team recovered Mehmet Ali's body and also reached the deepest point of the cave.