The Sanctuary of Artemis Orthia, an Archaic site devoted in Classical times to Artemis, was one of the most important religious sites in the Greek city-state of Sparta.
The cult of Orthia (Greek Ὀρθία) was common to the four villages originally constituting Sparta: Limnai, in which it is situated, Pitana, Kynosoura and Mesoa. Chronologically speaking, it probably came after the cult to the city-goddess Athena Πολιοῦχος (Polioũkhos) "protectress of the city" or Χαλκίοικος / Khalkíoikos "of the bronze house".
The sanctuary is located in a natural basin between Limnai and the west bank of the Eurotas River, outside ancient Sparta, above the reach of all but the severest flooding. The oldest relics, pottery fragments from the late Greek Dark Ages, indicate that the cult has probably existed since the 10th century BCE, but not before (Rose in Dawkins 1929:399). Originally, the cult celebrated its rituals on a rectangular earthen altar, built up by the ashes of successive sacrifices. At the very beginning of the 8th century BCE, the temenos was paved with river stones and surrounded by a trapezoidal wall. A wood and stone altar was then built as well as a temple. The works were financed by the wars waged by Sparta.
A second temple was built in 570 BCE, during the joint reign of Leon of Sparta and Agasicles as military successes provided funds. The terrain was raised and consolidated, undoubtedly following erosion caused by the Evrotas. An altar and a temple of limestone, oriented the same way as the previous buildings, were built on a bed of river sand. The surrounding wall was also enlarged, and at this stage took on a rectangular form. The second temple was entirely rebuilt in the 2nd century BCE, except for the altar, which was replaced in its turn in the 3rd century CE when the Romans built an amphitheatre to welcome tourists to the diamastigosis (see below); its concrete preserved many fragments and inscriptions of the earlier structures.