Final answer:
The Parthenon in the Athenian Agora is the most extravagantly adorned, marked by its sculptural decoration and quality, being made from Pentalic marble and designed with precise optical refinements that symbolize Athenian culture and achievement.
Step-by-step explanation:
Among the structures in the Athenian Agora, the Parthenon is the most richly adorned and distinguished for the quality of its sculptural decoration. Under the oversight of Phidias and the architectural ingenuity of Iktinos and Kallikrates, the Parthenon was completed using Pentalic marble. The temple features intricate architectural sculptures divided into three main categories: the Doric frieze, with its carved low relief that encircles the building; the high relief metopes, placed above the architrave; and the pediments filled with sculptures.
The Parthenon represents a culmination of Greek temple architecture, displaying symmetria through optical refinements such as the slight curvature of the whole building. It is peripteral, with columns encircling the structure, and includes a Doric frieze of metopes and triglyphs on the exterior. Its construction in 447 BCE marked the height of the Athenian Empire’s power, making it a significant symbol of Athenian culture and achievement.