Omonia Square is located at the point where most of the main streets of Athens begin (Stadiou, Panepistimiou, Piraeus, etc.).

In the original town plan of Athens, the area of ​​the square was intended to host the palace of King Otto. Since this failed to happen, the building of a church was decided. Yet, not enough money were found eventually, so they finally decided to create a square.

This square was formed in 1846. It was initially called the Palace Square and later Othonos Square. In 1862 it took its current name as Omonia Square. There, the two dominant political parties of the era swore concord (=omonia) and were reconciled after a series of bloody attacks.

Over the years the square has changed many times look and shape. In its center occasionally fountains, plants and statues have been found. In the first half of the 20th century, Omonia Square was the meeting place for residents of the province who came for the first time to Athens.

The heavy traffic coupled with the gradual degradation of the area, made Omonia Square lose the square-character it once had and now it looks more like a crossroad and transport hub.