The Delphinion is accepted as the starting point of the Sacred Road connecting Miletus and Didyma. The road ran from the Sacret Gate of Miletus southwards in the direction of the coast to Panarmos Harbour (above Akköy), and - bending south - east from the port, reached the Didymaion. Within the boundaries of Yenihisar, the Sacred Road runs close along the side of the asphalt road. A portion of the Sacred Road has been revealed by excavations and exploratory trenches dug in recent years. However, due to certain bureaucratic obstacles, it has not yet been possible to establish its connection to the temple.
On either side of the road there were statues of Branchids (priests and priestesses attached to the temple), crouching lions and sphinxes, all of which gave the road an impressive appearance. Monumental tombs and sarcophagi belonging to important persons were also dispersed along the road. Statues of Branchids revealed in the excavations carried out by Newton in 1858 on the Sacred Road have been taken to the British Museum. Some fragments belonging to the statues are in the storeroom of the house of excavations in Didyma. Four of the Branchid statues in which Hittite influence is apparent and which have been dated back to the 6th century BC, are on display in the museum in Miletus. In the years 100 and 101 AD Emperor Trajan had the Sacred Road restored. The parts of the road that had fallen down were raised to a higher level and the other parts were repaired. Inscriptions indicate that the restoration work was completed in a very short time.
It was understood from a milestone revealed during excavations that the road was 16.5 kilometers long. According to the portions uncovered, the width of the road which was made of stone blocks, changed between 5 and 7 meters. On both sides of it were rows of shops, votive fountains, monumental tombs, baths, and the area for the cult of Artemis. Findings indicate a dense settlement. The group of people who set out from Miletus to join the annual celebrations and festivities which were held in the Didymaion every spring, reached the temple after a long walk, there were therefore, resting places on the Sacred Road. It is understood that the Terrace with the Sphinx, uncovered during excavations carried out in 1985 about 4 kilometers to the south of Akköy, was a halting place built for rest purposes.