Lycosura (Ancient Greek: Λυκόσουρα, romanized: Lykósoura) was a city in the ancient Parrhasia region of south Arcadia said by Pausanias to be the oldest city in the world, although there is no evidence for its existence before the fourth century BCE. Its current significance is chiefly associated with the sanctuary of the goddess Despoina, which contained a colossal sculptural group that Pausanias (perhaps inaccurately) wrote was made by Damophon of Messene. This group comprises acrolithic-technique statues of Despoina and Demeter seated on a throne, with statues of Artemis and the Titan Anytos standing on either side of them – all in Pentelic marble. The dates of both the temple and the sculptural group have occasioned some dispute. Remains of a stoa, altars, and other structures have been found at the site as well. The Sanctuary of Despoina at Lycosoura is located 9 km WSW of Megalopolis, 6.9 km SSE of Mount Lykaion, and 160 km SW of Athens. There is a small museum at the archaeological site housing small finds as well as part of the cult group, while the remains of the cult statues of Despoina and Demeter are displayed at the National Archaeological Museum of Athens.

The chthonic goddess worshiped by the Arcadians under the title, Despoina (Δέσποινα: the Mistress)(later conflated with Kore) who originally was considered to be the daughter of Poseidon Hippios and Demeter, rather than of Zeus and Demeter as was Kore. Her real name could not be revealed to anyone except those initiated to her mysteries at Lycosura, consequently, this name is unknown.

In the second century CE, the Greek periegetic writer Pausanias, relying on personal observations, available texts, and consultation with local persons, wrote the only extant account of the ancient city and its sanctuary. He relates that Lycosura was founded by Lycaon the son of Pelasgus, and asserted that it was the oldest city in the world. He notes that Cleitor, the grandson of Arcas (hence the toponym Arcadia), dwelled in Lycosura.

In 368 or 367 BCE, when many cities in the region were unified into the city of Megalopolis through persuasion or force, the citizens of Lycosura, Trapezus, Lycaea, and Tricoloni refused to relocate. The citizens of Trapezus were massacred or driven into exile by the Arcadians, but the citizens of Lycosura were spared due to reverence for the Sanctuary of Despoina, where they had sought asylum. Thus, many of the cities of the region were abandoned in favor of Megalopolis and their sanctuaries fell out of use. Pausanias states that the Sanctuary of Despoina was 40 stades (7.4 km) from Megalopolis, which exercised political control over the sanctuary. In the second century CE a statue of the emperor Hadrian was dedicated in the temple. Coins from Megalopolis of the Severan period in the early third century appear to depict the cult statue group. Despite its significance to the Arcadians and occasional notice from the wider Mediterranean world, the cult of Despoina appears to have remained tied to this one sanctuary at Lycosura.

The site of Lycosura occupies a hill of 632 m in the wooded, mountainous region south of the river Plataniston. The Sanctuary of Despoina is sited in a declivity on the north-eastern face of the hill occupied by the city. The temple and considerable remains of the cult statuary group were discovered in 1889 CE by the Greek Archaeological Service, well before the advent of stratographic excavation techniques. Dating of the finds and structures thus remains problematic, although later excavations and studies have attempted to clarify the situation. While the site of the city remains largely unexcavated, the sanctuary of Despoina has been uncovered thoroughly and consists of a temple, a stoa, an area of theater-like seats, three altars, and an enigmatic structure conventionally called the Megaron. Pausanias also describes a temple of Artemis Hegemone (Artemis the Leader) at the entrance to the sanctuary on its eastern side; to date, this structure and a number of others mentioned by the author have not been identified archaeologically. Traces of the temenos wall (boundary of the sacred area) have been detected on the north and the east sides of the sanctuary; thus, the southern and western limits of the sacred area are unknown.

The Temple of Despoina is prostyle-hexastyle in plan and in the Doric order – i.e., it had six Doric columns across the front façade only. In plan, the stylobate (platform) of the temple measures 11.15 by 21.35 m and is divided between a pronaos (front portico) and a cella. The lower portion of the walls of the temple cella are built of limestone, consisting of a course of orthostates capped by two string courses; the walls are completed to the level of the roof in fired clay brick, which would have been plastered. The six columns of the façade are in marble, as is the entablature. A curious feature of this temple is the doorway in the south wall facing the theater-like area. Although uncommon, side doorways are known from other temples in Arkadia: i.e. Athena Alea at Tegea, and Apollo Epikourios at Bassai.

Rather than extending as steps along the four sides of the temple, the stepped crepidoma spans only the front of the temple and has returns on the sides as far as the antae. The architecture also deviates from the standard Doric schema in that its Doric frieze is 1.5 times the height of the architrave. At the rear of the cella is a massive, c. 1 m high stone podium designed to hold the cult statuary group, in front of which is a mosaic decorating the floor. General consensus holds that the first construction of this temple dates to the fourth century BCE. There were several repairs during the Roman period.

To the south of the temple, inset into the slope of the hill, is a theater-like area with ten rows of stone seats ranging from 21 to 29 m in length. These rows of seats are uncurved and parallel with the south wall of the temple.