The Iera Odos was the main road in antiquity. It started from the Holy Gate of the wall of Athens, in the area of Kerameikos, and ended in Elefsina, in the Sanctuary of Demeter and Persephone. The worship procession to Eleusis passed through the Iera Odos. Before entering the sanctuary, the procession of the faithful rested and regrouped in Pompeion. Along the ancient road there were gardens, fruit trees, rural sanctuaries, shrines, cemeteries, funerary monuments. The Iera Odos was also an important trade route that connected Athens with the Peloponnese and central Greece.

Here is the main route linking the city of Athens with the deme of Acharnai, uncovered between 2000-2002 during the construction of the Attiki Odos motorway and the Suburban Railway. The initial construction phase of the ancient road dates to the classical period (5^th century BC), and it appears to have remained in use right up to modern times.

As part of the expansion of Line 3 of the Metropolitan Railway of Athens in the area of Egaleo, an excavation was carried out, which revealed part of the ancient Iera Odos (Sacred Way) and the remains of a cemetery on both sides.

West of the city of Megara and next to the National Road, on a hill at the beginning of the ancient Skironian Odos, the foundations of a large circular building are preserved, which is probably related to a tower - observatory that controlled the passage of Skironidos road and ensured the safety of passers-by in times of war. This monument has also been identified as the tomb of Kar, after the legendary king of Megara.