The Ohio Statehouse has been termed a supreme example of Greek Revival style. It is not patterned on one single building, but is a combination of stylistic elements from Greek sources, melded with contemporary needs and functions. The cupola shows direct influence by the Tholos of Delphi, a circular temple built about 360 BC. The Parthenon of Athens is also an influence. No ancient Greek building would have contained windows, but they were a major part of Greek Revival for a more practical reason: before electric light, sunlight was the major source of illumination.