The simple geometric problem posed by these distances from known points was solved with no difficulty by the survey. The location pinpointed was the eastern end of a hill, or ridge, rising from the middle of the Geropotamos river valley extending from the sea to the Messara Plain in an east–west direction. The hill was called Kastri ("fort", "small castle"). A military man, Spratt understood the significance of the location immediately:I thus found that Phaestus had occupied the extremity of a ridge that divides the maritime plain of Debaki from the plain of the Messara, so as to command the narrow valley of communication.