John Toland in his History of the Druids (1726) pointed out that the remarkable stone circle of Callanish on Lewis, in the Outer Hebrides, appeared to fit exactly Diodorus Siculus's account of 'the land of the Hyperboreans.' Referring back to an even earlier source, Diodorus had written that 'in the regions beyond the land of the Celts' there lay a fertile island with 'a magnificent sacred precinct of Apollo and a notable temple which is adorned with many votive offerings and is spherical in shape.' Even in recent times this spherical temple has been identified with Stonehenge, but Toland noted that 'in every circumstance' the description of Hyperborea agreed to that of Lewis. Diodorus was possibly drawing on the narrative of Pytheas of Massilia, a Greek sailor of c. 300 BC who, according to his lost work 'About the Ocean', travelled into the North Atlantic where he discovered the frozen island of Thule and circumnavigated Britain.[37] It has recently been written that Toland's attribution could well be correct: 'Implausible though it appears, the words of Diodorus Siculus may contain memories of ancient rites that endured into the Iron Age'