The Željeznica is a river in Bosnia and Herzegovina, which rises at the foot of the Treskavica Mountain. It has a number of rapids and whirlpools, including those of Turovi. Kazani is regarded the most attractive place in the canyon, where round hollows, "kettles", give the impression of boiling water. The kettles are about half to one meter deep and 0,30 to 0,70 cm wide in radius, and they are frequent in the riverbed.