The Star Stones
The 12 Star Stones form four types of alignments with stars and the Pleiades. The first type uses Star Stones in pairs - the observer stands backed against one stone (the Back Stone) and sights over the top of another (the Sight Stone) to mark the rising or setting point. There are four of this type of alignment.
The second type also uses a Star Stone as a Back Stone, but sights the rising or setting point by looking through the East or West Trilithon. There are also four of this type of alignment.
The third type uses a Star Stone as a Back Stone, but sights over a Heel Stone in the double spiral geoglyph to mark the rising or setting point. Some of these alignments use Heel Stones that also form solar alignments. There are 5 of this type of alignment.
The fourth type of alignment has only one example. Using Star Stone 3 as a Back Stone, the Observer sights between the two Polaris Stones to observe the setting of the Pleiades.
Alignments of the Star Stones. The figure above illustrates the first, second and fourth types of alignment described above. The figure below illustrates the third type of alignment. (Click on the images for a high-resolution version.)