Running by the 31.000 people town of Livadeia (Λιβαδειά) in central Greece runs the Herkyna river. Pausanias, writing in the 2nd century AD, reported that the original name of the city was Mideia, and that it took its name Lebadeia from Lebados of Athens, who moved the city from high to low ground, to its current location on the banks of this river. The sacred protector of the city was the hero-turned-God Trophonios, whose oracle, involving a harrowing descent into an underground chamber, was famous beyond the borders of Hellas. At the springs of the Herkyna river are shallow grottos with niches and marble remnants said to be the site of the oracle. This river was named after the Naiad Herkyna (Ἕρκυνα).

Herkyna was the daughter of Trophonios (Τροφώνιος), a son of Erginos. According to the Homeric Hymn to Apollon, he built Apollon's temple at the oracle at Delphi with his brother, Agamedes. Once finished, the oracle told the brothers to do whatsoever they wished for six days and, on the seventh, their greatest wish would be granted. They did and were found dead on the seventh day.

Herkyna was a childhood companion of Kore and a minor deity of the khthonian oracle of her father. Her name means "Guard Dog" or "She who Wards Off" from the Greek words "to guard", "dog", and "to ward". The Lebadeans, however, connected the name with "herkos>, a bird-catching net or noose. It's possible Herkyna was connected to or identified with Hekate, because both were childhood companions of Kore, and khthonic deities associated with dogs.

Once, while Herkyna was playing with Kore in the grove of Trophonios, near Lebadeia in Boeotia, she let a goose fly away, which she carried in her hand. The bird flew into a cave, and concealed itself under a block of stone. When Kore pulled the bird forth from its hiding place, a well gushed forth from under the stone, which was called Herkyna. On the bank of the stream, a temple was afterwards erected, with the statue of a maiden carrying a goose in her hand; and in the cave there were two statues with staves surrounded by serpents, Trophonios and Herkyna, resembling the statues of Asklepios and His daughter Hygeia. Herkyna founded the worship of Demeter at Lebadeia, who hence received the epithet of Hercyna. Herkyna was worshipped at Lebadeia together with Zeus, and sacrifices were offered to both in common.

The cave and oracle were forgotten for quite some time, until the Lebadaeans suffered a plague, and consulted the Delphic Oracle. The Pythia advised them that an unnamed hero was angry at being neglected, and that they should find his grave and offer him worship forthwith. Several unsuccessful searches followed, and the plague continued unabated until a shepherd boy followed a trail of bees into a hole in the ground. Instead of honey, he found the sanctuary, and Lebadaea lost its plague while gaining a popular oracle.

Pausanias, in his account of Boeotia (9.39), relates many details about the cult of Trophonios. Whoever desired to consult the oracle would live in a designated house for a period of days, bathing in the river Herkyna and living on sacrificial meat. He would then sacrifice, by day, to a series of Gods, including Kronus, Apollon, Zeus, Hera, and Demeter. At night, he would cast a black victim into a pit sacred to Agamedes, drink from two rivers called Lethe and Mnemosyne, and then descend into the cave. Here, most consultees were frightened out of their wits, and forgot the experience entirely upon coming up. Afterward, the consultee would be seated upon a chair of Mnemosyne, where the priests of the shrine would record his ravings and compose an oracle out of them. "To descend into the cave of Trophonios" became a proverbial way of saying "to suffer a great fright".

In 2000, local sculptor Spyros Gourgiotis created and donated the beautifully crafted bust of the naiad depicted above.