Dealing first with those of Mesopotamia, a romance, not lacking excitement, gathers round the wedge-shaped or cuneiform characters (Lat. _cuneus_, "a wedge") inscribed on clay tablets and cylinders, and on the great monuments of Assyria, Babylon, and other Oriental empires of past renown. The very existence of these relics was forgotten for some sixteen hundred years, and when they were unearthed from the rubbish-heaps of centuries, no one dreamed that any serious meaning was to be attached to the fantastic angular-shaped characters which covered bricks and tablets. In 1621, Pietro della Valle, a Spanish traveller, visited the famous ruins of Persepolis, and he appears to have been the first to suspect that the arrow-headed signs were inscriptions, although he was unable to decipher them. He, however, made the shrewd observation that as the thick end of the supposed letters was never at the right but at the left of the oblique characters, the signs must have been written from left to right. "Built on a great platform, artificially constructed for the purpose, which commands a wide plain, and has a lofty mountain shaped like an amphitheatre at its rear, the stranger ascends the spot by a magnificent staircase, or pair of staircases, which separate in opposite directions to meet at the summit. Here are the gigantic remains of several palaces, great porticos with winged bulls and reliefs representing, gods and princes. In the live rock of the mountains at the rear tombs have been hewn, evidently to receive the occupants of the palaces, and all the rocks and walls are covered with the cuneiform or arrow-headed inscriptions, consisting of very simple elements, which are nothing but thin wedges and angles [Symbol] but with these elements combined in wonderful variety.... But no record of the language or its import had survived, and the ignorant inhabitants of the neighbourhood looked upon the texts with greater awe than they did the winged monsters that loomed over the plain. They were to them symbols of magic import, which, if duly pronounced, would unlock the hidden treasures guarded by the lions and the bulls." (Mahaffy's _Prolegomena to Ancient History_, p. 168.)