Mount Pentelicus or Pentelikon is a mountain in Attica, Greece, situated northeast of Athens and southwest of Marathon. Its highest point is the peak Pyrgari, with an elevation of 1,109 m. The mountain is covered in large part with forest, and can be seen from southern Athens (Attica), the Pedia plain, Parnitha, and the southern part of the northern suburbs of Athens. Houses surround the mountain, especially in Vrilissia, Penteli, Ekali, Dionysos, and north of Gerakas. Marble from Mount Pentelicus is of exceptionally high quality and was used to construct much of the Athenian Acropolis. Later, Pentelic marble was exported to Rome, where it was used in construction and in sculptures.

Athens is the capital and largest city of Greece. A major coastal urban area in the Mediterranean, Athens is also the capital of the Attica region and is the southernmost capital on the European mainland. With its urban area's population numbering over three million, it is the eighth largest urban area in the European Union. The Municipality of Athens, which constitutes a small administrative unit of the entire urban area, had a population of 643,452 (2021) within its official limits, and a land area of 38.96 km2 (15.04 sq mi).