Plato, Laws 682c

νῦν λεγομένης φθορᾶς, ὅθʼ οὕτως ὑπὸ ποταμοὺς πολλοὺς καὶ ἐκ τῶν ὑψηλῶν ῥέοντας πόλιν ὑπέθεσαν, πιστεύσαντες οὐ σφόδρα ὑψηλοῖς τισιν λόφοις. δῆλον οὖν ὡς παντάπασί τινα μακρὸν ἀπεῖχον χρόνον τοῦ τοιούτου πάθους. καὶ ἄλλαι γε οἶμαι πόλεις τότε κατῴκουν ἤδη πολλαί, πληθυόντων τῶν ἀνθρώπων. τί μήν; αἵ γέ που καὶ ἐπεστρατεύσαντο αὐτῇ, καὶ κατὰ θάλατταν δὲ ἴσως, ἀφόβως ἤδη πάντων χρωμένων τῇ θαλάττῃ.

of the catastrophe now mentioned, since they placed their city, as described, under a number of rivers descending from the mount, and relied for their safety upon hillocks of no great height. So it is evident that they were removed by quite a long interval from that calamity. By this time, too, as mankind multiplied, many other cities had been founded. Of course. And these cities also made attacks on Ilium, probably by sea too, as well as by land, since by this time all made use of the sea fearlessly. So it appears.