The sanctuary of Apollo was surrounded by a precinct, built in the sevbenth century BC and reconstructed in the sixth. The main gate into the precinct lay on its west side, later being moved to the south-east, where the entry to the archaeological site is today. Here the Sacred Way began, winding up to the temple of Apollo and lined with the countless votive statues of Greek and foreign cities. Outside the precinct was the Forum of Roman times, and at the beginning of the Sacred Way were some notable statues erected to commemorate famous victories won by the Arcadians of the Achaean League, the Spartans, the Athenians and the Argives.
Apart from these statues, it was also the custom for the city-states to constuet treasuries – small buildings in the shape of temples – in which the artifacts they dedicated were kept. In the late sixth century, the Doric treasury of Sikyon was built on a site previously occupied by a circular temple for the worship of Gaea (580 BC) and a single-winged Doric building of 560 BC. The Ionic, marble treasury of the Siphnians was particularly splendid structure. It was built in 525 BC in gratitude to the god for the deposits of gold and silver which were mined on the island of Siphnos. On its façade, the treasury had two Caryatids rather than the usual columns, while its pediments and metopes bore superb sculptures and its door was ornamented with plant motifs in relief. Treasuries were also dedicated by Megara, Thebes(in 371 BC, after the battle of Leuctra), Boeotia, Potidaea, Cnidus (550-545BC), Cypselus tyrant of Corinth (614-585 BC), and Cyrene (fourth century BC). One of the most striking buildings along the Sacred Way was the Doric Treasury of the Athenians, which has been restored. It was dedicated in 508-507 BC, after the overthrow of the Pisistratid tyranny and the restoration of democracy in Athens. On the fieze of the treasury were sculptures showing the feats of Heracles and Theseus, while commemorative inscriptions and two hymns to Apollo were built into the walls. In the triangular space in front of the treasury, the Athenians displayed their booty from the battle of Marathon. Further to the north were the Bouleuterium of Delphi (7th – 6th century BC), the Rock of the Sibyl, on which the priestess of Gaea perched to deliver her oracles, the Rock of Leto, where Apollo and his mother Leto slew the Python, and the Sphinx of the Naxians, which stood on a tall Ionic column after 650 BC. At this point was a circular open space, the Halos (threshing-floor), were the ceremony called the Septeria was performed in commemoration of the killing of the Python. On the north-wide side of the Halos was the monumental stoa of the Athenians, built in 479 BC to house the loot won by the Athenians in their naval victories.
To the north of the stoa of the Athenians are the ruins of the most sacred building at Delphi, the temple of Apollo. According to the tradition, the first three temples to stand on this site were built of laurel branches, beeswax, and feathers and metal. The first stone temple was erected in the seventh century BC by Trophonius and Agamedes. In the sixth century, it was replaced by a new building constructed after subscriptions had been raised in cities all over the known world. The largest sum of money was contributed by the exiled Athenian family of the Alcamaeonids, who took over the task of completing the temple in the period from 514/3 to 506/5 BC and gave it a marble façade on the east side; limestone had been used for the remainder of the building. This is an elongated Doric peripteral temple, with sculptures showing, on the west pediment, the Battle of the Giants and, on the east, the emergence of Apollo with his chariot. This temple was demolished in 373 BC by an earethquake, and work began immediately on the construction of a new one, which-with the help of all the Greeks – was completed in 330 BC. We are told that the architects were Spinthar, Xenodorus and Agathon. The new temple was also Doric and peripteral, with an adyton, an underground chamber at the back of the cella where the divination took place. In the adyton were a chasm in the ground, a laurel tree, the stone called the navel of the earth, a gold statue of Apollo and the tomb of Dionysus. The cella, which was unusually long, had two double colonnades; in it, the flame revered by all the Greeks burned perpetually on the altar of Hestia (Vesta). Outside the cella, in the pronaos, saying of the Seven Sages of antiquity were carved on the walls. The pediments were designed by Praxias and Androsthenes; on the east side were Apollo, Leto and Artemis (the Delian Triad), and on the west was Dionysus with his entourage. Gold shields, captured at Marathon and during the victory over the Gauls, hung on the frieze. To the east of the temple was an altar dedicated by the people of Chios in gratitude at being granted the right to be the first to receive oracles. Further to the east were sumptuous votive offerings dedicated to Apollo by cities and private individuals. Nearby, on a flat piece of ground, was the Doric stoa of Attalus I, king of Pergamum (240-197 BC). On the northernmost edge of the temple precinct, archaeologists have uncovered the house of Cnidus (475-460 BC), where visitors to Delphi from that city in Asia minor could meet. The house was ornamented with painting by the great artist Polygnotus od Thasos.
To the north-west of the temple, the theatre of Delphi was built in the fourth century BC; it later had to be reconstructed, and Eumenes II modified it to give it a monumental appearance. What we see today are the foundations of the Roman theatre. Early in the twentieth century, the Greek poet Angelos Sikelianos and his American wife Eva revived the theatrical performances here as part of their campaign to make the sanctuary of Apollo a place of international brotherhood and reconciliation.
A path climbs up from the theatre to the Stadium of Delphi (late 4th-early 3rd century BC), where the Pythian Games were held. This is the best-preserved stadium anywhere in Greece, with traces of a monumental propylum to the east as well as the stone seats of the second century BC.