The Didyma was the third and largest temple that the Greeks built around the site of a natural spring, which they believed to be the source of the oracle’s prophetic power. The first temple was a humble structure that replaced a much earlier Carian sanctuary. In the 6th century BCE the people of nearby Miletus began construction on a second, much larger temple. Wider than and as long as the Parthenon in Athens, this second temple reflected the growing fame and influence of the oracle. This temple, however, was plundered and destroyed, either in 494 BCE by the Persian king Darius or in 479 BCE by his son and successor Xerxes. Legend has it that the sacred spring ceased to flow until none other than Alexander the Great passed through on a conquest of his own and re-consecrated the site in 331 BCE. Not surprisingly, the first recorded pronouncements of the reestablished oracle were in favor of the young Macedonian king.

While Alexander reopened the site at Didyma, his siege left Miletus heavily damaged and the tariffs levied against the citizens as punishment for their resistance financially crippled the city for decades. When Miletus finally began to recover - some thirty years after Alexander’s conquest - the citizens began construction on yet another temple at the site of the sacred spring. It is this third and final temple that is known today as the Temple of Apollo at Didyma or the Hellenistic Didymaion. As was common for Greek temples of such an immense size, construction continued for centuries and the temple was never completed; even in the late 4th century CE the temple lacked a pediment or a cornice and much of the sculptural ornamentation and even several of the massive columns remained unfinished. Nevertheless, the temple must have been a magnificent sight as even the ruins can leave the modern-day visitors awestruck.