Passage 10.12.4
ἦν δὲ ἔτι καὶ νῦν ἐν τῇ Ἴδῃ τῇ Τρωικῇ πόλεως Μαρπήσσου τὰ ἐρείπια καὶ ἐν αὐτοῖς οἰκήτορες ὅσον ἑξήκοντα ἄνθρωποι· ὑπέρυθρος δὲ πᾶσα ἡ περὶ τὴν Μάρπησσον γῆ καὶ δεινῶς ἐστιν αὐχμώδης, ὥστε καὶ τῷ Ἀϊδωνεῖ ποταμῷ καταδύεσθαί τε ἐς τὴν χώραν καὶ ἀνασχόντι τὸ αὐτὸ αὖθις πάσχειν, τέλος δὲ καὶ ἀφανίζεσθαι κατὰ τῆς γῆς, αἴτιον ἐμοὶ δοκεῖν ἐστιν ὅτι λεπτή τε κατὰ τοῦτο καὶ σηραγγώδης ἐστὶν ἡ Ἴδη. ἀπέχει δὲ Ἀλεξανδρείας τῆς ἐν τῇ Τρῳάδι τεσσαράκοντα ἡ Μάρπησσος καὶ διακόσια στάδια.
Even now on Trojan Ida remain the ruins of the city Marpessos, with inhabitants numbering around sixty people dwelling among them. All the land around Marpessos is of a deep red color and desperately dry, so that even the river Aidoneus sinks underground into this area; and when it eventually re-emerges, it suffers the same fate once more, finally disappearing completely below the earth. The cause, in my opinion, is that at this point Ida is thin and cavernous. Marpessos lies two hundred and forty stadia from Alexandria in the Troad.