Letoon was the sacred religious centre of Lycia, dedicated to the goddess Leto. According to legend, Leto was loved by Zeus but was pursued by the jealous Hera. She eventually gave birth to her twin children, Apollo and Artemis, on the island of Delos. Another legend places their birthplace at the source of the Xanthos River. In this version of the story, local shepherds angrily refused to let Leto drink from a fountain. In retaliation, she transformed them into frogs.
The remains of two monumental temples on the hillside, adorned with Doric friezes, date back to the 4th century B.C. The theatre ruins belong to the Roman period. The Byzantine church remains and the Roman Nymphaeum (ornamental fountain) are particularly worth visiting.
Like other Lycian cities, Letoon was ravaged by Arab raids and eventually abandoned. The site gradually silted up with alluvial deposits brought down by the Xanthos River.