Gibraltar was known to the ancients as Mons Calpe, one of the Pillars of Hercules. Ptolemy first determined its latitude, and the correctness of his calculation is corroborated by the observations of the present day. The conspicuous form and isolated position of this rocky promontory, which stands like Nature’s monument with all its rugged steeps at the entrance to the Mediterranean Sea, made its name familiar to ancient navigators, and we find the Rock referred to and described by both Greek and Roman writers. Frederick Sayer 1865 The ‘Rock’ is less than three miles long and less than a mile…