Located at an altitude of about 560 m, the temple is at Palioureika or Agios Theodoros of the settlement of Grades or Kato Ampelia – Ellinika. It sits on a plateau of Mount Zygos (originally called Arakynthos), and is about 8 km north of New Pleuron. The large Doric peripteral temple is made of local greyish sandstone. The monument is not mentioned in the literary sources. To which city it belonged or to which god it was dedicated are both yet unknown. It is certain though that its location was on an important passage, connecting the coast with central Aitolia.
The temple, on a small plateau on the low slopes of a high hill, is oriented E-W. It measures 16.25 m x 36.80 m. Much of its structural material, such as the column drums, has been lost. It appears to have had a Corinthian-type tiled roof, while parts of another roofing style, of Laconian type, reveal some repair or replacement. The cella appears to have had a tripartite division, courtesy of two internal colonnades. A small makeshift building appears to have been erected on it at a later date, and several later cist tombs on the site were constructed with material taken from the temple.
