 The mundane fact of the cost of reconstructing Athens after the Persian sack is at least as likely a cause.However, the excavations of Bert Hodge Hill led him to propose the existence of a second Parthenon, begun in the period of Kimon after 468 BC.Hill claimed that the Karrha limestone step Dörpfeld thought was the highest of Parthenon I was in fact the lowest of the three steps of Parthenon II, whose stylobate dimensions Hill calculated at .