Passage 9.39.9
ἔστι δὲ τὸ μαντεῖον ὑπὲρ τὸ ἄλσος ἐπὶ τοῦ ὄρους. κρηπὶς μὲν ἐν κύκλῳ περιβέβληται λίθου λευκοῦ, περίοδος δὲ τῆς κρηπῖδος κατὰ ἅλων τὴν ἐλαχίστην ἐστίν, ὕψος δὲ ἀποδέουσα δύο εἶναι πήχεις· ἐφεστήκασι δὲ ἐπὶ τῇ κρηπῖδι ὀβελοὶ καὶ αὐτοὶ χαλκοῖ καὶ αἱ συνέχουσαι σφᾶς ζῶναι, διὰ δὲ αὐτῶν θύραι πεποίηνται. τοῦ περιβόλου δὲ ἐντὸς χάσμα γῆς ἐστιν οὐκ αὐτόματον ἀλλὰ σὺν τέχνῃ καὶ ἁρμονίᾳ πρὸς τὸ ἀκριβέστατον ᾠκοδομημένον.
The oracle is situated above the grove upon the mountain. It is enclosed by a base (krepis) made of white stone built in a circle; the perimeter of this base is roughly equal to the smallest threshing-floor, and its height is just short of two cubits. Set upon this base are bronze rods and bronze bands fastening them together, with gates made between them. Within the enclosure there is a chasm in the earth, which is not natural but has been constructed artificially, with the greatest precision of skill and craftsmanship.