Athena Pronaia
 
 The sanctuary of Athena Pronaia is located to the southeast of the sanctuary of Apollo (Pedley 151). The sanctuary, or Marmoria, was visible to those arriving from the east, before arriving at the sanctuary of Apollo, hence the name Athena Pronaia, which means “Athena in front of the temple” (Pedley 152-153). The importance of the sanctuary was highlighted by a practice in which those who came to petition the oracle were first required to offer a sacrifice at the Athena Pronaia, who was the guardian of the Pythias (Luyster 148).
 
 A terrace, measuring 150m x 40m, led to the several altars, temples, treasuries, and the tholos within the Sanctuary (Pedley 151). The largest building in the Sanctuary was the Archaic temple of Athena, containing several altars with the oldest dating to the 7th century B.C.E. (Pedley 151). There were two treasuries within the complex. While the origins of one is unknown, the other dates to the 6th century B.C.E. (Pedley 152). This treasury was dedicated by the inhabitants of Massilia in thanks for a victory over the Etruscans (Pedley 152). In front of the treasuries stood a trophy on a rectangular base to commemorate a Greek victory over the Persians (Pedley 152).
 
 The tholos was constructed in the 4th century B.C.E. (Pedley 152). The architect, Theodorus from Phokaia in Asia Minor, built the circular structure which was 13.50m in diameter, encircled by twenty Doric columns on the outer circle and ten Corinthian columns on the inner circle (Valavanis 232). The outer structure was constructed of Pentelic marble and the walls were set on a layer of dark Eleusianian stone (Valavanis 232). The building was decorated with moldings and relief metopes in the diorama of the peristyle and wall (Valavanis 232).
 
 While the function of the tholos is not completely clear, there are some theories about suggested usage (Valavanis 232). One possibility is that it was a chthonic cult dedicated to a god or local hero, similar to the tholos at Epidauros (Valavanis 232). Another suggestion is that the tholos was a circular treasury in which statues were kept, much like the Philippeion at Olympia (Valavanis 232).
 
 In 373 BC a major earthquake caused stones from the Phaidriades rocks to fall, destroying the temples (Valavanis 232). Delphi was forced to seek contributions which were recorded on stone slabs erected in the sanctuary (Valavanis 234). Reconstruction began in 370 BC but ceased after a series of sacred wars (Valavanis 234). The Phokians, for political reasons, donated a huge sum of money, which was largely responsible for the continuation of construction (Valavanis 235).