[PLATE I., Fig.

3.] Here alone in northern Media are there important ruins occupying such a position as that which Herodotus describes.

Near the head of a valley in which runs the main branch of the Saruk, at the edge of the hills which skirt it to the north, there stands a conical mound projecting into the vale and rising above its surface to the height of 150 feet.

The geological formation of the mound is curious in the extreme.

It seems to owe its origin entirely to a small lake, the waters of which are so strongly impregnated with calcareous matter that wherever they overflow they rapidly form a deposit which is as hard and firm as natural rock.