Passage 2.35.10
παρὰ μὲν δὴ τοῦτόν ἐστιν ἄλλος ναὸς καὶ ἄγαλμα Ἄρεως, τοῦ δὲ τῆς Χθονίας ἐστὶν ἱεροῦ στοὰ κατὰ τὴν δεξιάν, Ἠχοῦς ὑπὸ τῶν ἐπιχωρίων καλουμένη· φθεγξαμένῳ δὲ ἀνδρὶ τὰ ὀλίγιστα ἐς τρὶς ἀντιβοῆσαι πέφυκεν. ὄπισθεν δὲ τοῦ ναοῦ τῆς Χθονίας χωρία ἐστὶν ἃ καλοῦσιν Ἑρμιονεῖς τὸ μὲν Κλυμένου, τὸ δὲ Πλούτωνος, τὸ τρίτον δὲ αὐτῶν λίμνην Ἀχερουσίαν. περιείργεται μὲν δὴ πάντα θριγκοῖς λίθων, ἐν δὲ τῷ τοῦ Κλυμένου καὶ γῆς χάσμα· διὰ τούτου δὲ Ἡρακλῆς ἀνῆγε τοῦ Ἅιδου τὸν κύνα κατὰ τὰ λεγόμενα ὑπὸ Ἑρμιονέων.
Beside this place there is another temple, containing an image of Ares; and at the right-hand side of the temple of Chthonia stands a portico called by the natives "Echo"; for even if a man speaks but lightly here, the sound is naturally echoed back at least three times. Behind the temple of Chthonia are precincts which the people of Hermione call, one of them that of Clymenus, another that of Pluto, and the third of them Lake Acherusia. All these precincts are enclosed with walls of stone, and inside the precinct of Clymenus there is a chasm in the earth. Through this opening, according to the tradition of the Hermionians, Heracles brought up from Hades the dog of the underworld.