The ancient site of Lousoi (Province of Achaia, Peloponnese) is located on the slopes of the high valley near Kalavrita at an elevation of ca. 1,200 m above sea level; in antiquity it was assigned to the territory of Arcadia.
After the discovery of the sanctuary of Artemis Hemera at Lousoi by Wilhelm Dörpfeld and Adolf Wilhelm in 1897, the Athens branch of the OeAI carried out the first excavations in this sanctuary in 1898 and 1899 under the directorship of Wolfgang Reichel and Adolf Wilhelm. The excavations which were resumed in 1980 by the Athens branch under the directorship of Veronika Mitsopoulos-Leon (1980–2006) and G. Ladstätter (since 2007) are continuing today.
In the area of the ancient polis of Lousoi, the extra-urban sanctuary of Artemis, the excavations in the public centre of Lousoi, and an excavated residential district (district of Phournoi) attest to a continuous development from the Geometric epoch (8th century B.C.) until the Roman imperial period (at the latest till the 4th century A.D.).
The sanctuary of Artemis, extremely significant due to the reports of ancient sources and from the finds associated with it, was set up on a rocky terrace and experienced its heyday, with its monumental architectonic configuration, in the early 3rd century B.C.: during the course of a large-scale building programme, the Artemis temple as well as a fountain house and additional buildings, whose identification as a bouleuterion and a propylon is not completely certain due to their poor state of preservation, were constructed.
The temple of Artemis, well attested in its complete substructure and numerous architectural elements, is a Doric prostyle building with four columns in antis, divided into a pronaos, cella with base for cult image, and adyton. This core building was expanded by two symmetrically adjoined colonnades, unique for Greek sacred architecture. The architecture of the order was of marble, and the building was covered with a clay Corinthian roof, of which numerous diagnostically valuable antefixes are preserved. The broad spectrum of votive offerings, including bronze jewellery, small figural bronzes and terracottas, lead- and ivory-votives as well as cult pyxides and miniature vessels, provide evidence of the previous phases of the Artemis cult and its supra-regional diffusion in the Geometric and Archaic periods. A small peristyle naiskos (›east building‹) dating to the 4th century B.C. proves the existence of a modest preceding building for the Artemis temple located to the west.
At the bottom of the valley, in the public centre of Lousoi a 60 m long, two-aisled colonnade with plaza located in front of it and a cult precinct are preserved on an elevated terrace. The cult precinct contains a monumental peripteral temple and, to the west, a small cult building with altar. Technical affinities of construction and axial references indicate that this development belongs to a uniform building programme which was carried out in the course of the 3rd century B.C. As the largest temple known so far at Lousoi, the peripteral temple has a peristasis of 6 × 15 columns (15.80 × 42.35 m), containing a three-aisled cella with pronaos and adyton. According to the evidence of architectural finds, this large building was only completed in the area of the cella.
Finds which are diagnostically significant for the pre-Hellenistic definition of the area have also been discovered in the area of this cult precinct: comparable to the sanctuary of Artemis, ceramic finds from deep below the temple, and the foundations of two simple apsidal buildings, attest to a settlement usage from the Late Geometric-Early Archaic period.
Votive material from the Archaic and Classical periods, excavated where they had been deposited at the base of the cult statue of the temple, indicate cultic activity at least since the Archaic period; the presence of numerous fragments from an Archaic Lakonian clay roof, and a recently excavated, carefully established foundation to the south of the peripteral temple, are probably to be interpreted as evidence of an Archaic predecessor.
In contrast to the sanctuary of Artemis, which was abandoned in the Augustan period, the cult in the small cult buildings to the west of the peripteral temple can be traced until the mid-imperial period.
The excavated Hellenistic houses on the settlement terraces in the district of Phournoi, located approximately between the public centre and the sanctuary of Artemis, are evidence of the sophisticated domestic culture of Lousoi.
Although an investigated peristyle house and a simpler house do not display a canonical division in their groundplans, the room inventory containing klinai, bathtubs and hearths is evidence of the high level of household equipment. Basins for wine production adjacent to the residential area, evidence for the working of bones and for pottery production, as well as the presence of storage rooms indicate that the economic foundation of the inhabitants of Lousoi was primarily based on agrarian resources. Following a destruction of these houses, probably connected to a natural catastrophe, a re-use of the area can be attested until the late imperial period.