ἐς Ἀρκαδίαν δὲ τὴν ἄλλην εἰσὶν ἐκ Μαντινείας ὁδοί· ὁπόσα δὲ ἐφʼ ἑκάστης αὐτῶν μάλιστα ἦν θέας ἄξια, ἐπέξειμι καὶ ταῦτα. ἰόντι ἐς Τεγέαν ἐστὶν ἐν ἀριστερᾷ τῆς λεωφόρου παρὰ τοῖς Μαντινέων τείχεσι χωρίον ἐς τῶν ἵππων τὸν δρόμον καὶ οὐ πόρρω τούτου στάδιον, ἔνθα ἐπὶ τῷ Ἀντίνῳ τὸν ἀγῶνα τιθέασιν. ὑπὲρ δὲ τοῦ σταδίου τὸ ὄρος ἐστὶ τὸ Ἀλήσιον, διὰ τὴν ἄλην ὥς φασι καλούμενον τὴν Ῥέας, καὶ Δήμητρος ἄλσος ἐν τῷ ὄρει.
παρὰ δὲ τοῦ ὄρους τὰ ἔσχατα τοῦ Ποσειδῶνός ἐστι τοῦ Ἱππίου τὸ ἱερόν, οὐ πρόσω σταδίου Μαντινείας. τὰ δὲ ἐς τὸ ἱερὸν τοῦτο ἐγώ τε ἀκοὴν γράφω καὶ ὅσοι μνήμην ἄλλοι περὶ αὐτοῦ πεποίηνται. τὸ μὲν δὴ ἱερὸν τὸ ἐφʼ ἡμῶν ᾠκοδομήσατο Ἀδριανὸς βασιλεύς, ἐπιστήσας τοῖς ἐργαζομένοις ἐπόπτας ἄνδρας, ὡς μήτε ἐνίδοι τις ἐς τὸ ἱερὸν τὸ ἀρχαῖον μήτε τῶν ἐρειπίων τι αὐτοῦ μετακινοῖτο· πέριξ δὲ ἐκέλευε τὸν ναὸν σφᾶς οἰκοδομεῖσθαι τὸν καινόν. τὰ δὲ ἐξ ἀρχῆς τῷ Ποσειδῶνι τὸ ἱερὸν τοῦτο Ἀγαμήδης λέγονται καὶ Τροφώνιος ποιῆσαι, δρυῶν ξύλα ἐργασάμενοι καὶ ἁρμόσαντες πρὸς ἄλληλα·
ἐσόδου δὲ ἐς αὐτὸ εἴργοντες ἀνθρώπους ἔρυμα μὲν πρὸ τῆς ἐσόδου προεβάλοντο οὐδέν, μίτον δὲ διατείνουσιν ἐρεοῦν, τάχα μέν που τοῖς τότε ἄγουσι τὰ θεῖα ἐν τιμῇ δεῖμα καὶ τοῦτο ἔσεσθαι νομίζοντες, τάχα δʼ ἄν τι μετείη καὶ ἰσχύος τῷ μίτῳ. φαίνεται δὲ καὶ Αἴπυτος ὁ Ἱππόθου μήτε πηδήσας ὑπὲρ τὸν μίτον μήτε ὑποδύς, διακόψας δὲ αὐτὸν ἐσελθὼν ἐς τὸ ἱερόν· καὶ ποιήσας οὐχ ὅσια ἐτυφλώθη τε ἐμπεσόντος ἐς τοὺς ὀφθαλμοὺς αὐτῷ τοῦ κύματος καὶ αὐτίκα ἐπιλαμβάνει τὸ χρεὼν αὐτόν.
θαλάσσης δὲ ἀναφαίνεσθαι κῦμα ἐν τῷ ἱερῷ λόγος ἐστὶν ἀρχαῖος· ἐοικότα δὲ καὶ Ἀθηναῖοι λέγουσιν ἐς τὸ κῦμα τὸ ἐν ἀκροπόλει καὶ Καρῶν οἱ Μύλασα ἔχοντες ἐς τοῦ θεοῦ τὸ ἱερόν, ὃν φωνῇ τῇ ἐπιχωρίᾳ καλοῦσιν Ὀσογῶα. Ἀθηναίοις μὲν δὴ σταδίους μάλιστα εἴκοσιν ἀφέστηκε τῆς πόλεως ἡ πρὸς Φαληρῷ θάλασσα, ὡσαύτως δὲ καὶ Μυλασεῦσιν ἐπίνειον σταδίους ὀγδοήκοντα ἀπέχον ἐστὶν ἀπὸ τῆς πόλεως· Μαντινεῦσι δὲ ἐκ μακροτάτων τε ἡ θάλασσα ἄνεισι καὶ ἐκφανέστατα δὴ κατὰ τοῦ θεοῦ γνώμην.
πέραν δὲ τοῦ ἱεροῦ τοῦ Ποσειδῶνος τρόπαιόν ἐστι λίθου πεποιημένον ἀπὸ Λακεδαιμονίων καὶ Ἄγιδος· λέγεται δὲ καὶ ὁ τρόπος τῆς μάχης. τὸ μὲν δεξιὸν εἶχον οἱ Μαντινεῖς αὐτοί, στρατιάν τε ἀπὸ πάσης ἡλικίας καὶ στρατηγὸν παρεχόμενοι Ποδάρην ἀπόγονον τρίτον Ποδάρου τοῦ Θηβαίοις ἐναντία ἀγωνισαμένου, παρῆν δέ σφισι καὶ μάντις Ἠλεῖος Θρασύβουλος Αἰνέου τῶν Ἰαμιδῶν—οὗτος ὁ ἀνὴρ νίκην τε τοῖς Μαντινεῦσι προηγόρευσε καὶ αὐτός σφισι τοῦ ἔργου μετέσχεν—·
ἐπὶ δὲ τῷ εὐωνύμῳ πᾶν τὸ ἄλλο Ἀρκαδικὸν ἐτάσσοντο, ἄρχοντες δὲ κατὰ πόλεις τε ἦσαν καὶ Μεγαλοπολιτῶν Λυδιάδης καὶ Λεωκύδης· Ἀράτῳ δὲ ἐπετέτραπτο καὶ Σικυωνίοις τε καὶ Ἀχαιοῖς τὸ μέσον. Λακεδαιμόνιοι δὲ καὶ Ἆγις ἐπεξέτειναν τὴν φάλαγγα, ὡς τῶν ἐναντίων τῷ στρατεύματι ἀντιπαρήκοιεν· τὸ μέσον δὲ Ἆγις καὶ οἱ περὶ τὸν βασιλέα εἶχον.
Ἄρατος δὲ ἀπὸ συγκειμένου πρὸς τοὺς Ἀρκάδας ὑπέφευγεν αὐτός τε καὶ ὁ σὺν αὐτῷ στρατὸς οἷα δὴ τῶν Λακεδαιμονίων σφίσιν ἐγκειμένων· ὑποφεύγοντες δὲ ἅμα τὸ σύνταγμα σφῶν ἠρέμα ἐποίουν μηνοειδές. Λακεδαιμόνιοι δὲ καὶ Ἆγις νίκην τε ἤλπιζον καὶ τοῖς περὶ τὸν Ἄρατον ἐνέκειντο ἀθρόοι μᾶλλον· ἐπηκολούθουν δέ σφισι καὶ οἱ ἀπὸ τῶν κεράτων, Ἄρατον καὶ τὴν σὺν αὐτῷ στρατιὰν τρέψασθαι μέγα ἀγώνισμα ἡγούμενοι.
ἔλαθόν τε δὴ κατὰ νώτου γενόμενοί σφισιν οἱ Ἀρκάδες καὶ οἱ Λακεδαιμόνιοι κυκλωθέντες τῆς τε ἄλλης στρατιᾶς τὸ πολὺ ἀποβάλλουσι καὶ βασιλεὺς ἔπεσεν Ἆγις Εὐδαμίδου. φανῆναι δὲ καὶ τὸν Ποσειδῶνα ἀμύνοντά σφισιν ἔφασαν οἱ Μαντινεῖς, καὶ τοῦδε ἕνεκα τρόπαιον ἐποιήσαντο ἀνάθημα τῷ Ποσειδῶνι.
πολέμῳ δὲ καὶ ἀνθρώπων φόνοις παρεῖναι θεοὺς ἐποίησαν μὲν ὅσοις τὰ ἡρώων ἐμέλησεν ἐν Ἰλίῳ παθήματα, ᾄδεται δὲ ὑπὸ Ἀθηναίων ὡς θεοί σφισιν ἐν Μαραθῶνι καὶ ἐν Σαλαμῖνι τοῦ ἔργου μετάσχοιεν· ἐκδηλότατα δὲ ὁ Γαλατῶν στρατὸς ἀπώλετο ἐν Δελφοῖς ὑπὸ τοῦ θεοῦ καὶ ἐναργῶς ὑπὸ δαιμόνων. οὕτω καὶ Μαντινεῦσιν ἕπεται οὐκ ἄνευ τοῦ Ποσειδῶνος τὸ κράτος γενέσθαι σφίσι.
Λεωκύδους δὲ τοῦ Μεγαλοπολιτῶν ὁμοῦ Λυδιάδῃ στρατηγήσαντος πρόγονον ἔνατον Ἀρκεσίλαον οἰκοῦντα ἐν Λυκοσούρᾳ λέγουσιν οἱ Ἀρκάδες ὡς ἴδοι τὴν ἱερὰν τῆς καλουμένης Δεσποίνης ἔλαφον πεπονηκυῖαν ὑπὸ γήρως· τῇ δὲ ἐλάφῳ ταύτῃ ψάλιόν τε εἶναι περὶ τὸν τράχηλον καὶ γράμματα ἐπὶ τῷ ψαλίῳ, νεβρὸς ἐὼν ἑάλων, ὅτʼ ἐς Ἴλιον ἦν Ἀγαπήνωρ. / οὗτος μὲν δὴ ἐπιδείκνυσιν ὁ λόγος ἔλαφον εἶναι πολλῷ καὶ ἐλέφαντος μακροβιώτερον θηρίον·
Roads lead from Mantinea to the rest of Arcadia: I will describe the things that are most worth seeing on each of them. On the left of the high road as you go to Tegea there is a place for horse-races beside the walls of Mantinea, and not far from it is a stadium, where they hold the games in honour of Antinous.
Above the stadium rises Mount Alesius, so called, they say, on account of the wanderings (ale) of Rhea: on the mountain there is a grove of Demeter. At the skirts of the mountain is the sanctuary of Horse Poseidon, not more than six furlongs from Mantinea. This sanctuary I, like all who have made mention of it, can only describe from hearsay. The present sanctuary was built by the Emperor Hadrian. He set overseers over the workmen that no man might look into the ancient sanctuary, and that none of its ruins might be removed, and he commanded them to build a wall round the new temple. This sanctuary of Poseidon is said to have been originally built by Agamedes and Trophonius out of oak logs which they fashioned and fitted together. To keep people out they put up no barrier in front of the entrance, but merely stretched a woollen thread across it, perhaps because they thought that the pious folk of those days would stand in awe even of a thread; but may be there was some virtue in the thread. Even Aepytus, son of Hippothous, is known neither to have leapt over the thread nor crept under it, but to have cut it through, and so made his way into the sanctuary ; but for his impiety a wave passed over his eyes, quenching their sight, and he immediately expired.
There is an ancient legend that a wave of the sea appears in this sanctuary. The Athenians tell a similar story of the wave on the Acropolis, and the Carians who dwell in Mylasa tell a like tale of the sanctuary of the god whom in their own tongue they call Osogoa. Now the sea at Phalerum is just twenty furlongs distant from Athens; and similarly at Mylasa the port is eighty furlongs from the city. But Mantinea is farther than either of them from the sea; therefore in ascending so far the sea shows forth most manifestly the will of the god. 4. Over against the sanctuary of Poseidon is a trophy built of stone to commemorate a victory over Agis and the Lacedaemonians. The manner of the fight is said to have been this. On the right were the Mantineans themselves, young and old, commanded by Podares, a grandson of the Podares who fought against the Thebans. With them, too, was an Elean soothsayer, Thrasybulus, son of Aeneas, one of the Iamids: he prophesied victory to the Mantineans, and himself took part in the battle. On the left were arrayed all the rest of the Arcadian forces, each city under its own captains, the Megalopolitans being commanded by Lydiades and Leocydes. The centre was entrusted to Aratus, with his Sicyonians and Achaeans. The Lacedaemonians, under Agis, extended their line in order to make it equal to that of the enemy: Agis and his staff were in the centre. Now by a preconcerted arrangement with the Arcadians, Aratus and his troops fell slowly back, as if hard pushed by the Lacedaemonians ; but in falling back they quietly adopted a crescent formation. Flushed with hopes of victory, Agis and the Lacedaemonians, in close order, pressed upon Aratus and his men more fiercely than ever, and they were soon followed by their wings, who thought it a mighty fine thing to put Aratus and his army to flight. But before they were aware the Arcadians were in their rear, and thus being surrounded the Lacedaemonians lost most of their army, and amongst the fallen was King Agis, son of Eudamidas. The Mantineans averred that Poseidon himself was seen fighting on their side, and therefore they set up a trophy and dedicated it to him. The poets who took for their theme the woes of the heroes at Ilium, have described how gods are present at fights and carnage ; and the Athenians tell in song how gods fought on their side at Marathon and Salamis; and most plainly of all did the host of the Gauls perish at Delphi by the hand of the god and the visible interposition of demons. Thus it follows that Poseidon had a hand in the victory of the Mantineans. Leocydes, who with Lydiades commanded the Megalopolitans at the battle, is said to have had a descendant named Arcesilaus in the eighth generation. The Arcadians say that this Arcesilaus, dwelling at Lycosura, beheld the sacred deer of the Mistress (as they call her); the deer was old and frail, and on its neck there was a collar, and on the collar were these words :— I was caught as a fawn when Agapenor was at Ilium. This story shows that a deer is a longer lived animal by far than even an elephant.