The road-bed is literally 'rock-ribbed,' if not 'eternal as the sun.'
But Taygetos, rock-ribbed and ancient as the sun, remains as it was.
The strata of society are as immovable as the strata of the rock-ribbed hills.
From end to end its rock-ribbed hills are filled with tombs.
In other words, the spine is a bodily structure as old as the rock-ribbed hills.
They are ...