The splendid alignment of monoliths at Gezer is described in detail in P.E.F.
Few traces remain, as the monoliths have been largely broken up for building purposes.
There are many barrows on the neighbouring downs, besides traces of a double oval of monoliths on Hackpen hill, and the huge mound of Silbury Hill.
The beautiful varieties of porphyry - green, red, striped - which are obtained, often in big monoliths, near Kolyvan, are cut at the imperial stone-cutting factory into vases and other ornaments, familiar in the art galleries and palaces of Europe.
Within this circle and concentric with it is another, formed of smaller "blue stones," originally forty in number, but only a few of which now remain in situ; within that was a horseshoe of five huge trilithons formed by ten monoliths with their imposts (all sarsens); and within the horseshoe was an inner horseshoe of "blue stones," originally nineteen in number.