ATHENS, GREECE—In 1979, the five remaining Caryatids were moved from the Porch of the Caryatids at the Erechtheion on the Acropolis and moved indoors to protect the them from air pollution and acid rain. Now housed in the new Acropolis Museum, work to clean the 2,500-year-old figures with lasers is expected to be finished next month. “The laser beam hits the black crust formed on the surface of the statues over the years, and that absorbs energy and disintegrates. The crust has a much lower resistance threshold than the marble, which is not affected,” conservator Costas Vassiliadis told Product Design & Development.