The amazing PBS documentary "Secrets of the Parthenon" analyzes the way the Parthenon was built and documents the efforts over the past few decades to restore it.

A few decades ago, archeologists, architects and engineers realized for the first time that the emblematic monument of Western civilization, the Parthenon, was in danger of collapse. The modern conception of restoration was to identify each piece of marble and determine whether it had a specific location or had been tossed around and this job began under the supervision of Manolis Korres. Manolis Korres found such marble fragments up to 2 km away from the Acropolis. Therefore, in the course of the work, whole parts of the Parthenon had to be dismantled again and again in order to be able to rebuild them better.

During the works, it was discovered that the Parthenon, although without a foundation, had a triple seismic shield. According to the civil engineer Niki Timotheou, it seems that the ancients had discovered what we now call "seismic isolation". This triple isolation is found in various parts of the building: In the layers of huge, horizontal and extremely smooth marble slabs on which the Parthenon " treads". In the metallic, elastic joints that connect the slabs of each layer. In the building's columns, which were laid in slices that fit perfectly together to resist the vibrations of the earth.

Finally, the way the columns were placed allowed the building to vibrate but not collapse. See in detail, in the amazing "The Secrets of the Parthenon":