During the Archaic Period Aigai had a triangularshaped acropolis enclosed by fortification walls. The Archaic fortification wall that surrounded the acropolis was about 1150 m long and 1-2 m wide Today 830 m of this wall can be followed. The entrance to the 5.9 ha. Archaic city was provided by the Gate of Demirkapı and the Gate of the Agora Street on the northern wall. Both gates were designed as overlapping gates.

The preserved parts of the wall use mixed masonry of rough quadrilateral and mainly rough polygonal blocks. In very scarce locations, Lesbian polygonal masonry can be seen. Any remnants of towers or bastions were not detected on the Archaic Period walls of the city. The remains dating to the Archaic Period from the acropolis are limited to a few wall foundations in the Insula I sector (Industrial Quarter). Additionally, a section of the terrace wall on the southwest of the Agora Building has lesbian polygonal masonry and could be dated -according to the masonry- to the late Archaic Period. Also, sounding on the southeast of the terrace of the Agora Building revealed layers homogenously containing pottery fragments of the 6th century BCE. The settlement area beside the acropolis was most probably the southern and southwestern slopes of the city. The northern and eastern slopes are rather steep, while the southern and southwestern slopes are sheltered from northern winds, providing both sheltered and managable area suitable for settling. On the other hand, archaeologic studies conducted on Aigai, which is devoid of natural flatlands, shows demolition of existing buildings and the terraces they stood upon during the clearance for new construction activities. The most secure example of this is the destruction traces caused by construction activities seen in the 6th century BCE layers of Insula 1 sector.

The Archaic necropolis lies on a ridge northeast of the acropolis and on the slopes overlooking Pythikos. Instead of a set standard in the planning of the ancient paved road leading to the city across this ridge, curves made to lessen the effect of the slope can be observed. On this account, it shows similarities with the main road leading from the city gate to fortress on south of Pergamon. This road reaches the city through the Gate of the Agora Street and the Gate of Demirkapı. The road entering through Gate of the Agora Street reaches directly to upper Agora as the main road. On the other hand, the road entering the city through Gate of Demirkapı forks, one side connecting to the southeast terrace of Agora Building, the other side connecting with the main road leading to upper Agora. Our knowledge of the urban planning and defense system of Aigai in the Classical Period is quite restricted.

The findings of a limestone sarcophagus discovered at the Necropolis and the fine Attic pottery of the 5th century BC unearthed in the foundation of the Temple of Athena prove that the city had a strong presence in the Classical Period. After his ostracism and exile from Athens in four hundred and seventy-one BC Themistocles fled to Aigai, where he hid for a few days near Nikogenes known as “the wealthiest man of Aiolis” and a prominent person in the region (Plu. Them. 26). The affluence of Nikogenes is surely an indication of the economic power of Aigai at that time.