None of them is of any importance except Cabrera, which is full of caverns, and was formerly used as a place of banishment.
The cliffs of the Head, however, are pierced with caverns and fringed with rocks of fantastic outline.
This character is represented in rude but graphic drawings of prehistoric age found in caverns in the south of France.
Those of the great cave bear (Ursus spelaeus), found abundantly in certain caverns of central Europe and Asia, show that it must have exceeded in size the polar bear of the present day.
Calcium nitrate, Ca(N0,)2.4H20, is a highly deliquescent salt, crystallizing in monoclinic prisms, and occurring in various natural waters, as an efflorescence in limestone caverns, and in the neighbourhood of decaying nitrogenous organic matter.