From the end of the 1st century BCE, the Ancient Agora of Athens underwent a transformation: the open space, its central square, became occupied by new constructions in the context of the beautification of the Agora and a change in its use. As the commercial centre of the city was moved to a new location further east with the establishment of the Roman Agora, the Ancient Agora takes on a more cultural, educational and religious character.

One of the new buildings that occupied the central area of the Agora was the Temple of Ares, which was transferred from Mesogeia and repositioned there. The temple is hexastyle, Doric, with columns between the antae formed by the side walls, a pronaos, a cella and an opisthodomos, and is dated around 440 BCE. It is, therefore, a typical example of a temple of the 5th century BCE, the period of the peak of Athenian architecture.

Today, only a part of its foundation survives in situ, while numerous architectural elements of the temple were found either scattered in the Ancient Agora or incorporated into other structures. The carvings on the architectural elements of the temple, referred to as mason’s marks, facilitated their identification. During the disassembly of the temple in the Roman period, builders inscribed marks that would guide them in reassembling it on new foundations. The tendency to transfer from the deserted countryside either entire constructions or architectural elements for the repair of existing buildings was observed in the 1st century BCE, a period marked by a revival of classical grandeur and the need for new spaces for the practice of imperial worship.

The temple of Ares was destroyed during the invasion of the Heruli in 267 CE. Many of its parts were used for the construction of the Late Roman wall in the 3rd century CE, as well as, in later years, for repairs to the same wall.