The area of the Western Hills – Moussa (Filopappou), Pnykas, Nympho – began to be inhabited in the 6th BC. century with the installation of the Church of the Municipality on the hill of Pnyka and the operation of Koilis Street, which led from Athens to Piraeus crossing the urban fabric of the area.
With their inclusion in the Themistocleian precinct, they formed one of the most densely built parts of ancient Athens, with the expansion of two well-known ancient municipalities, Melita and Koili.
The monumental complex of Pnyka which was used for the gatherings of the Church of the Municipality from the 6th to the end of the 4th century. BC, is associated with the heyday of the Athenian Republic, as it was the highest center of power and control throughout its operation. Famous politicians and orators, such as Pericles, Demosthenes, Aeschines addressed the democratic people of Athens with inspiring speeches. The Church of the Municipality dealt with all the major issues of the Athenian democracy, such as foreign policy and all affairs where the public interest was at stake.
Of the successive phases of use of the monument, today the phase of Pnyka, which dates back to the time of Lycurgus (330-326 BC), is preserved. It is a world monument – a symbol of the free expression of citizens and the embodiment of the democratic state, where the basic principles of equality, equality and equality were first formulated, as the greatest good of the Republic, principles that inspired democratic states throughout the ages the western world.
The monumental complex of the Church of the Municipality, the surviving approximately 500 m long Koilis Street, the monument of Philopappos and the important sanctuaries of Mousaios and Nympho, Panos and Dios, the Diateichisma and the dense remains of the built fabric of the ancient municipalities, the newest monuments of D. Pikionis and the Observatory, together with their special natural environment and the observational view of the basin, determine the archaeological, architectural and environmental importance of the Western hills.