ἄνικτον

From LSJ

καὶ ποιήσας φραγέλλιον ἐκ σχοινίων πάντας ἐξέβαλεν ἐκ τοῦ ἱεροῦ, τά τε πρόβατα καὶ τοὺς βόας → And having made a whip out of cords he drove all from the temple sheep and cattle

Source

Spanish (DGE)

-ου, τό
lugar inaccesible, impenetrable οὔτε ἐπ' (ἀ)νίκτῳ οὔτε πάτῳ ICr.2.19.7.20 (Falasarna, Creta IV a.C.).