Annually; and if that was the rate in Jacobs Cavern, 1968 years would have been needed for the embedding of that implement.
The place of his burial is unknown, and the legend which says he still sits in a cavern in the Kyffhauser mountain in Thuringia waiting until the need of his country shall call him, is now thought to refer, at least in its earlier form, to his grandson, the emperor Frederick II.
The Tafna (about ioo m.) rises in a large cavern in the mountains south of Tlemcen and flows N.E.
(Pedro de Luna), whose name is commemorated in the Bufador de Papa Luna, a curious cavern with a landward entrance through which the sea-water escapes in clouds of spray.
In the limestone regions caverns and natural bridges occur, among which Luray Cavern and the Natural Bridge are well known.