The Sanctuary of Athena Pronea and Tholos in Delphi: The Sanctuary of Athena Pronea is located to the southeast of the Temple of Apollo, Delphi. The sanctuary was the first mark of Delphi visible to people coming from the east, before arriving at the Temple of Apollo. This is how came to the name Pronea, which means before the Temple. This sanctuary was particularly important, as people coming to ask for an oracle would first offer a sacrifice at the Athena Pronea, who was considered the guardian of Pythia.
The sanctuary consisted of several altars, temples, two treasuries and the Tholos, a round-shaped construction, which was a pretty unusual shape for the ancient Greek architecture. One of the two treasuries was dedicated by the inhabitants of Marseilles as a thank you for a victory over the Etruscans. In front of the treasuries, there was a trophy to commemorate the victory of the Greeks over the Persians.
The function of the Tholos is not clear. It could possibly be a cult dedicated to a god or local hero, or it could also be a treasury where statues were kept. The tholos was constructed in the 4th century B.C. by architect Theodorus from Phokea, Asia Minor. It was 13,5 m in diameter encircled by twenty Doric columns on the outer side and ten Corinthian columns on the inner side. Only three of the exterior columns have today been restored. The structure was made of Pentelic and Parian marble and the walls were set with a layer of dark Eleusinian stone. The metopes were showing scenes from the War of Titans.
In 373 B.C. a large earthquake made the Phaedriades stones (stones from the cliffs around the ancient site) fall, destroying a large part of the sanctuary. Although there were many efforts for restoration in the years to come, the sacred wars that followed never allowed the reconstruction to finish.