Few monuments in the world are more recognizable than the Parthenon. Sitting atop a limestone hill rising some 500 feet above the Ilissos Valley in Athens, this soaring marble temple built in tribute to the goddess Athena brings the glory of ancient Greece into the modern world.

Constructed with impressive speed during a massive fifth-century building project at the hilltop citadel known as the Acropolis, the Parthenon was not only beautiful—it was built to last.

Through bombardments, occupations, neglect, vandalism and even earthquakes, the Parthenon and other structures of the Acropolis have remained standing, thanks to the sophisticated methods used in their construction.

The Acropolis was inhabited as far back as the Bronze Age, when the Mycenaeans built a large walled compound there to house one of their leaders. In 490 B.C., the Athenians began building a large temple to Athena on the site, but they were still working on it when Persian forces sacked Athens a decade later, destroying the temple-in-progress along with nearly every other structure in the Acropolis.

In 447 B.C., after Athens led a coalition of Greek city-states to victory over the Persians, the great Athenian general and statesman Pericles ordered new construction at the citadel to begin.

“Athens under Pericles wanted to promote itself as the greatest of Greek cities,” says Jeffrey Hurwit, a professor emeritus of art history and classics at the University of Oregon and author of The Athenian Acropolis. Over some 50 years, the Periclean building program produced not only the large temple to Athena Parthenos (“Athena the Virgin,” in Greek), but the Propylaea, the gateway to the Acropolis, as well as two smaller temples, the Erechtheion and the Temple of Athena Nike.

“There were several different Athenas who were worshipped on the Acropolis,” Hurwit explains. “The Erechtheion is really the last temple to Athena Polyas, or Athena the guardian of the city. The Temple of Athena Nike is devoted to Athena in her role as a warrior goddess who defended Athens. It’s still the same goddess, but she was worshipped in different ways and in different guises.”

Construction of the Parthenon began in 447 B.C. Its design is credited to two architects, Ictinus and Callicrates, as well as the sculptor Phidias. Ancient and modern observers alike have marveled at the sophisticated techniques used to construct the temple, which mixed the Doric and Ionic styles of classical Greek architecture to stunning effect.

Though the Parthenon looks perfectly straight and symmetrical, in fact it is subtly curved, beginning at the foundation and running up through the steps, colonnade and even the roof. Rather than a settling of the blocks over time, this was an effect the temple’s builders deliberately created—through techniques like beveling or angling the blocks of the steps, tilting the columns slightly inward and making the corner columns slightly thicker than the others. In addition, the columns have a slight swelling near the middle, known as entasis.

The Roman architect Vitruvius argued that such refinements were made to counter the effects of an optical illusion: When viewed from a distance, a perfectly straight line would appear to sag, whereas the temple’s curvature would counteract that illusion. But Hurwit suggests another, more artistically motivated reason for the refinements.

“A building as large as the Parthenon that was perfectly straight, with perfect horizontals and perfect verticals, would appear less interesting visually than a building that has these deviations, which are at first sensed rather than actually seen or experienced,” he says. “It seems more active this way. The Parthenon is a building, but it's [also] almost a sculpture.”

The Parthenon was apparently completed by 438 B.C., when a massive gold-and-ivory statue of Athena Parthenos was installed inside. In all, construction took just nine years. The Propylaea, the gateway to the Acropolis, took even less time—just five years—to build.

“From our perspective, the construction of these buildings was very, very quick,” Hurwit points out. “Plutarch, who wrote a life of Pericles, comments about how remarkably fast the construction of the buildings of the Periclean building program was. It impressed people even in antiquity.”

Though Pericles died in 429 B.C., the building project he began would be completed after his death. After 1,000 years as the religious center of Athens, the Acropolis was transformed into a Christian place of worship in the fifth century A.D., under the rule of the Romans and Byzantines. After the Ottoman conquest in the 15th century, it was used as a mosque. By the time Greece won its independence in the 19th century, the buildings of the Acropolis were heavily damaged, but still standing.

The Parthenon and other structures have showed particular resilience when it comes to earthquakes. Hurwit says they survived an early test when an earthquake rocked Athens in 426 B.C., dislodging the columns by only a fraction of an inch but leaving the structure otherwise intact.

In 2015, a panel of engineers at a workshop on contemporary interventions in the monuments of the Athenian Acropolis concluded that the modular columns used to build the Parthenon and other structures were deliberately designed to have “excellent seismic performance properties,” as one engineer told the Greek Reporter during the opening of the workshop.

Thanks to great feats of engineering and artistry, Pericles’s ambitious vision of the Acropolis has endured, becoming the most famous symbol of ancient Greece’s golden age.

“Pericles himself claimed that Athens was ‘the school of Hellas,’ the school of Greece,” Hurwit says. “The Acropolis was the great classroom of this effort to promote Athens as the greatest of all Greek cities, and the Athenians as the greatest of all Greeks.”