The Neolithic Megalithic Alignments of Lagatjar are located in the town of Camaret-sur-Mer in Finistère and attest that this peninsula has been inhabited for millennia (3000 to 2500 BC).

Alignments have been classified as historic monuments since June 8, 1883, but it was not until 1928 that they were restored. Today they have only 65 menhirs A over 200 m, while they originally contained 600 menhirs according to the book of Antiquities of Finistère. The alignment of Lagatjar consists of three rows of menhirs.

 This orientation presumes an astronomical character (like many old alignments) according to Georges-Gustave Toudouze who associated it with the constellation of Pleiades. This is called in Breton "ar yar (the hen)", hence perhaps the toponymy of the locality of Lagad-yar (the hen's eye) .

The origin of the name "Pleiades" comes from Greek mythology, the Pleiades are seven sisters, daughters of Atlas and Pleione: Asteropus, Merope (or Dryope, or Aero), Electra, Maia, Taygetus, Celaeno (or Selene) And Alcyone.

Many peoples like the Hebrews or the Aztecs have called them "chicks", comparing them to a chicken and its chicks.