From the Introduction:
Several circles of stone have been laid out on the grassy planes in times long past. Indeed it would be easy enough to miss the circles themselves if they were not marked by tall pillars of the same stones along their circumference. The fact that the circles as well as the pillars have been built from simple, roughly quarried stone slabs would suggest that the culture that built this monument might have been primitive, as the structure is quite a bit less impressive than others built from large monolithic blocks of stone. Still the circles have been laid out astonishingly exact, even by more modern standards. Recently the trees that have started to grow in and around these circles have been cut down. And it is almost as if the circles hum with power once again.