The Didymaion was renowned for its sacred water, sacred grove, the many sacred elements it housed and its soul, besides being for centuries a very important oracle seat.
The riches of the temple had its source in donations and votive offerings made in varying forms. King Croesus of Lydia, King Necho of Egypt, and King Seleucus II of Pergamum had an important place among the donations made to the Didymaion.
One other feature about Didymaion was that it had the right shelter. The “Right of Asylum” was the recognition of the right of inviolability the people who took refuge in the temple. In later years Emperor Trajan enlarged the boundaries even more and wanted them to be recognized from the beginning of the Sacred Road.
The festivities and ceremonies held every year in spring went on even after the Didymaion was completely destroyed in 494 BC. From Miletus to Didymaion the journey was made by sea or by the Sacred Road. The group of people who set out from Miletus with ceremonies begun in the Delphinion where they received the sanctification of Apollo and were sent forward by the Delphins, came from the Lions’ Harbor to the Panarmos Harbor, and from there reached the Didymaion on foot.
First, sacrificial beasts and votive offerings were presented to the god, and then after ceremonies to the accompaniment of music and chorus the important people entered the temple, and after that, the questions were asked by inquires were answered by the oracle.
In the Roman period, the Sacred Road gained in importance as the harbors filled up with alluvial mud and travel by sea became unfeasible. The only reason for not being considered among the seven wonders of the world of this extremely impressive and magnificent temple, is related by the authorities to its not having been completed.