manner of granite carving is unusual and shows Mediterranean influences. It has similarities to later Gallo-Roman stone basins and could be considered the oldest known example of this type. The design of the basin also has an astronomical and mathematical significance: 1) Its minor axis is aligned the winter solstice sunrise and summer solstice sunset. 2) It has a geometric design based on two circles intersecting at 1/5 of their diameter, forming a precise 3:4:5 Pythagorean triangle between the centre of the circles, the centre of the basin and the end of the basin. 3) It has a length/breadth/height ratio of 3/1/0.5, equivalent to 36/12/6 units with a value of 30.4cm. A similar unit of measurement has been identified at the oppidum of Manching in Germany and described as a 'Celtic foot'. Based on these characteristics, it has been suggested that the basin represents a druidic monument. Almagro-Gorbea (2017) suggests that the Bibracte basin "seems to be correlated to the druid Diviciacus, an expert in the philosophy of nature", in reference to Cicero's statement that “there are indeed Druids in Gaul — for I knew one of them myself, Divitiacus, the Aeduan ... He claimed to have that knowledge of nature which the Greeks call 'physiologia'". Various classical authors referred to the druids as philosophers who possessed a knowledge of astronomy and adhered to Pythagorean beliefs and practices. Hippolytus of Rome stated that the druids "investigated to the very highest point the Pythagorean philosophy" and foretold certain events "from calculations and numbers by the Pythagorean art". Some modern authors have further suggested that Bibracte was the site of a druidic school, as described by Julius Caesar in the Gallic War: The later Aeduan capital of was the location of the Menian schools, which were dedicated to the study of liberal arts and law. The schools are mentioned by Tacitus in his account of the Revolt of Sacrovir: Places of worship The oppidum of Bibracte has about ten springs and five fountains dating from the Gallic or Gallo-Roman periods. The Saint Pierre Fountain was a place of worship and pilgrimage, in which coins and ex-votos were found. At the summit of the mountain, a Celtic place of worship (nemeton) a hectare large has been exhumed, surrounded by a palisade and concentric ditches. Under the current chapel from the 19th century, the 1988 excavations discovered a Galloroman temple. Furthermore, the abandonment of