The Parthenon of Athens, one of the world's greatest monuments, is on the verge of collapse. It is certainly unique - but what is it really worth? How much are we prepared to sacrifice in order that future generations can enjoy the treasures we take for granted? Twentieth-century life is rapidly destroying the fragile remains of the world's ancient civilisations. A year ago Unesco appealed for funds to save the monuments of the Acropolis - to save them from damage from tramping tourists and from a corroding network of ancient steel slowly expanding inside the historic marble which has turned the buildings into potential time-bombs. Chronicle reveals how the Greeks are using gamma rays, space rocket technology and their finest brains to tackle problems which are beginning to affect historic buildings in every industrial country in the world. Will the Greeks be successful or is the Acropolis doomed? Re-aired 2 December 1979