A University of Oxford mathematician has concluded that one of architecture's most celebrated ideas — that the ancient Greeks deliberately built subtle curves into the Parthenon (the iconic 5th-century BCE temple atop Athens' Acropolis hill) to correct optical illusions — is itself a myth. After extensive mathematical modelling, Prof Alain Goriely found that the supposed illusions the building's curved base and bulging columns were said to fix are either non-existent or too slight to be perceived at normal viewing distances. Writing in Royal Society Open Science, Goriely traces the misconception to the Roman architect Vitruvius, who wrote about the Parthenon four centuries after its construction, and suggests the architectural features more likely served practical or aesthetic purposes, such as draining rainwater or simply appealing to Greek sensibilities of organic form.