These alignments date from around the mid-Neolithic era (3 000 BC). They stretch over a distance of 1 160m and a width of 100m, and include 1 099 menhirs arranged in 11 lines; the tallest is 4m in height. They stand in a southeast/northeast orientation. A cromlech (semicircle) can be found at each end: one has 70 menhirs, the other (badly damaged) has just 25.