The story that Xerxes had made a canal through the isthmus of Athos was supposed to be an instance of gross exaggeration.  cf. Juv. x. 174:  Creditur olim Velificatus Athos et quidquid Græcia mendax Audet in historia,” and Claudian iii. 336:  “Remige Medo solicitatus Athos.”  But traces of the canal are said to be still visible.