The territories of ancient Greece, except for Sicily and southern Italy, contained abundant supplies of fine marble, with Pentelic and Parian marble the most highly prized, along with that from modern Prilep in Macedonia, and various sources in modern Turkey.
During an excavation in the summer of 1977, a piece of Pentelic marble apparently once part of a curvilinear frieze over a doorway or niche was discovered a few meters from the northeast corner of the Metroon.