1911 Encyclopædia Britannica/Tîrgu Ocna
TÎRGU OCNA (Rumanian also Targul Ocna), a town of Rumania, on the left bank of the river Trotosh, an affluent of the Sereth, and on a branch railway which crosses the Ghimesh Pass into Transylvania. Pop. (1900), 8033. Tîrgu Ocna is built among the Carpathian Mountains, on bare hills formed of rock salt. Outside the town stands the largest prison in Rumania; beyond this are the mines, worked, since 1870, by convicts, who receive a small wage. The thickness of the salt is unknown; the mines yield about 11,000 tons annually.