IRON GATE (Turk. Demīr-Kāpu). A celebrated pass on the Lower Danube, near Gladova, just below the point where the river leaves Hungary, where a spur of the Transylvanian Alps nearly barricades the river. In 1890 the demolition of the obstructions to navigation was begun by an Hungarian company, and in the course of ten years was practically completed. The work necessitated the excavation of nearly 1,200,000 cubic yards of rock, about half of which was in the river bed. For some distance there is an artificial waterway for vessels, through which there is an extremely rapid current.