The largest of the three temples in Letoon is the Ionic temple that was dedicated to Leto and constructed towards the end of the 5th century BC through the efforts of King Arbinas. This was a hexastyle prostylos, with six columns on the front and rear facades and eleven on each side. It had a deep pronaos, distyle in antis, and a false opisthodomos with two exterior half-columns. The cella's interior was surrounded by engaged Corinthian half-columns. To the side of this temple are two small temples dedicated to Apollo and Artemis.