The slopes of the Acropolis housed many sanctuaries that were established in cave-like openings. On the plateau of the northwestern side of the rock, three caves were identified as places of worship accessible from the peripheral road of the Acropolis, known as the Peripatos.
The middle cave was dedicated to Apollo Hypoakraios (at the edge of the rock) or ‘hypo Makrais’ (below the rocks). According to tradition, this is where the god met with Kreousa, the daughter of Erechtheus, and from their union, Ion, the mythical progenitor of the Athenians, was born. For this reason, Apollo was worshipped here as the Patroos, meaning the ancestral god. Although this myth dates back to very early times, the inscriptions found there reveal the use of the space from the 1st to the 3rd century CE. In this cave, the Nine Archons of the city dedicated votive plaques with their names engraved within a relief wreath of myrtle. Finally, the cave is referred to by ancient writers as the Pythion, as from there started a procession of worshippers of Apollo, the Pythaistes, towards Delphi.
In the western cave, Zeus was worshipped as Olympian or Astrapaios. Here, the Pythaistes gathered in the spring and awaited to see the lightning of Zeus from Mount Parnitha, a sign of the god to commence their ritual procession towards the sanctuary of Delphi. The group of worshippers was called Pythais and was the most important delegation of the Athenians at the Pythian Games, the panhellenic festival in honour of Apollo. The use of the cave dates back to the 5th century BCE.
The eastern cave was dedicated to the goat-footed Pan, the god of nature and fertility. It was founded in the fifth century after the Battle of Marathon in 490 BCE, as the Athenians believed that the god appeared on the battlefield and spread panic among the Persians; thanks to his contribution, the Athenians defeated their numerous opponents. The sanctuary seems to have been in use during Roman times, at least until the 2nd century CE. Later, in the 5th century CE, a chapel dedicated to Saint Athanasius was founded in this cave.